diff --git a/cmd/felis/api.go b/cmd/felis/api.go
index 171aebf..4bbeab4 100644
--- a/cmd/felis/api.go
+++ b/cmd/felis/api.go
@@ -172,9 +172,10 @@ func cmdAPI(args []string, stdout, stderr io.Writer) int {
 	buildCfg.FelisImage = os.Getenv("FELIS_IMAGE")
 	buildJobs := build.NewK8sJobs(cl, buildCfg)
 	builder := &build.Builder{
-		Store:  build.NewPGStore(drv.DB()),
-		Jobs:   buildJobs,
-		Config: buildCfg,
+		Store:    build.NewPGStore(drv.DB()),
+		Jobs:     buildJobs,
+		Config:   buildCfg,
+		Outcomes: build.NewK8sOutcomes(clientset, buildCfg),
 	}
 	go probeBuildUserNamespaces(ctx, buildJobs, buildCfg, stderr)
 
@@ -533,6 +534,9 @@ func buildConfig(cfg *config.Config) build.Config {
 		MaxConcurrent:         cfg.Registry.MaxConcurrentBuilds,
 		TrivyDBRepository:     cfg.Registry.TrivyDBRepository,
 		TrivyJavaDBRepository: cfg.Registry.TrivyJavaDBRepository,
+		ScanFailOn:            cfg.Registry.ScanFailOn,
+		ScanFailUnfixed:       cfg.Registry.ScanFailUnfixed,
+		ScanAccept:            cfg.Registry.ScanAccept,
 		// The submit lane's derived context URLs live here; the fetch step's
 		// service token goes nowhere else.
 		ContextOrigin: internalAPIBaseURL(),
diff --git a/cmd/felis/run.go b/cmd/felis/run.go
index 41d3fde..3b1aced 100644
--- a/cmd/felis/run.go
+++ b/cmd/felis/run.go
@@ -23,6 +23,7 @@ Commands:
   files             List/read/write one file in a stopped server's world (internal Job entrypoint)
   egress-gate       Hold a build pod until its egress NetworkPolicy is enforced (internal Job entrypoint)
   fetch-context     Fetch and extract a submission's build context (internal Job entrypoint)
+  scan-gate         Apply the scan policy to a build's Trivy report and hand felis-api the report and SBOM (internal Job entrypoint)
   push-image        Push a scanned image tarball to the registry (internal Job entrypoint)
   mirror-build-tools Copy kaniko, trivy and Trivy's DBs into the registry (run by felis-build-tools.timer)
   registry-gate     Authorize registry writes in front of registry:2 (internal sidecar entrypoint)
@@ -61,6 +62,7 @@ var commands = map[string]func(args []string, stdout, stderr io.Writer) int{
 	"files":              cmdFiles,
 	"egress-gate":        cmdEgressGate,
 	"fetch-context":      cmdFetchContext,
+	"scan-gate":          cmdScanGate,
 	"push-image":         cmdPushImage,
 	"mirror-build-tools": cmdMirrorBuildTools,
 	"registry-gate":      cmdRegistryGate,
diff --git a/cmd/felis/scangate.go b/cmd/felis/scangate.go
new file mode 100644
index 0000000..c965cb3
--- /dev/null
+++ b/cmd/felis/scangate.go
@@ -0,0 +1,166 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"strings"
+
+	"felis.lolicon.best/internal/build"
+)
+
+// maxScanDocument bounds each document scan-gate reads: a modpack report lists a
+// few thousand packages, far below this. Tests shrink it.
+var maxScanDocument int64 = 64 << 20
+
+// cmdScanGate is the build pod's verdict step, after trivy wrote its full JSON
+// report and trivy convert wrote the CycloneDX SBOM. It applies the scan policy
+// to the report, prints the verdict and every blocking finding, then appends the
+// verdict, the report and the SBOM to its log as the envelope felis-api keeps on
+// the build (build.WriteScanEnvelope). It exits 1 when a finding blocks, which
+// fails the pod before the push step runs, and 2 when the report cannot be read,
+// so a scan that produced nothing usable never admits an image.
+func cmdScanGate(args []string, stdout, stderr io.Writer) int {
+	fset := flag.NewFlagSet("scan-gate", flag.ContinueOnError)
+	fset.SetOutput(stderr)
+	reportPath := fset.String("report", "", "trivy JSON report (required)")
+	sbomPath := fset.String("sbom", "", "CycloneDX SBOM to keep with the report")
+	failOn := fset.String("fail-on", strings.Join(build.DefaultScanFailOn, ","), "comma-separated severities that block the image")
+	failUnfixed := fset.Bool("fail-unfixed", false, "block on vulnerabilities that have no fixed release too")
+	accept := fset.String("accept", "", "comma-separated vulnerability ids and secret rule ids that never block")
+	termLog := fset.String("termination-log", "/dev/termination-log", "where the one-line verdict goes for the pod status")
+	if err := fset.Parse(args); err != nil {
+		return 2
+	}
+	// A stray argument is a policy the gate would otherwise drop without a word
+	// (a comma split out of --fail-on, say).
+	if fset.NArg() > 0 {
+		fmt.Fprintf(stderr, "felis scan-gate: unexpected argument %q\n", fset.Arg(0))
+		return 2
+	}
+	sevs, err := build.ParseSeverities(*failOn)
+	if err != nil {
+		fmt.Fprintf(stderr, "felis scan-gate: --fail-on: %v\n", err)
+		return 2
+	}
+	accepted, err := build.ParseScanAccept(*accept)
+	if err != nil {
+		fmt.Fprintf(stderr, "felis scan-gate: --accept: %v\n", err)
+		return 2
+	}
+	if *reportPath == "" {
+		fmt.Fprintln(stderr, "felis scan-gate: --report is required")
+		return 2
+	}
+	fail := func(msg string) int {
+		fmt.Fprintln(stderr, "felis scan-gate: "+msg)
+		writeTerminationLog(*termLog, msg)
+		return 2
+	}
+	report, err := readScanDocument(*reportPath)
+	if err != nil {
+		return fail("the scan report is unreadable: " + err.Error())
+	}
+	policy := build.ScanPolicy{FailOn: sevs, FailUnfixed: *failUnfixed, Accept: accepted}
+	summary, err := build.Summarize(report, policy)
+	if err != nil {
+		return fail("the scan report is unreadable: " + err.Error())
+	}
+	env := build.ScanEnvelope{Summary: summary, Report: report}
+	if *sbomPath != "" {
+		switch sbom, err := readScanDocument(*sbomPath); {
+		case err == nil:
+			env.SBOM = sbom
+		case errors.Is(err, fs.ErrNotExist):
+			fmt.Fprintf(stdout, "felis scan-gate: no SBOM at %s; keeping the report alone\n", *sbomPath)
+		default:
+			return fail("the SBOM is unreadable: " + err.Error())
+		}
+	}
+
+	printScanVerdict(stdout, summary)
+	written, err := build.WriteScanEnvelope(stdout, env)
+	if err != nil {
+		return fail("could not write the scan envelope: " + err.Error())
+	}
+	for _, doc := range written.Summary.Omitted {
+		fmt.Fprintf(stderr, "felis scan-gate: the %s is too large to keep with the build and was left out\n", doc)
+	}
+	if summary.Blocked {
+		writeTerminationLog(*termLog, summary.Reason())
+		return 1
+	}
+	writeTerminationLog(*termLog, "the scan passed")
+	return 0
+}
+
+// printScanVerdict writes the human half of scan-gate's log.
+func printScanVerdict(w io.Writer, s build.ScanSummary) {
+	var counts []string
+	for _, sev := range build.Severities {
+		counts = append(counts, fmt.Sprintf("%s %d", sev, s.Counts[sev]))
+	}
+	fmt.Fprintf(w, "felis scan-gate: %d packages; findings: %s\n", s.Packages, strings.Join(counts, ", "))
+	unfixed := "vulnerabilities with no fixed release do not block"
+	if s.Policy.FailUnfixed {
+		unfixed = "vulnerabilities with no fixed release block too"
+	}
+	fmt.Fprintf(w, "felis scan-gate: blocking on %s (%s)\n", strings.Join(s.Policy.FailOn, ", "), unfixed)
+	if len(s.Policy.Accept) > 0 {
+		matched := 0
+		for _, f := range s.Findings {
+			if f.Accepted {
+				matched++
+			}
+		}
+		fmt.Fprintf(w, "felis scan-gate: accepted ids, never blocking: %s; listed findings under them: %d\n", strings.Join(s.Policy.Accept, ", "), matched)
+	}
+	if !s.Blocked {
+		fmt.Fprintln(w, "felis scan-gate: nothing blocks this image")
+		return
+	}
+	fmt.Fprintln(w, "felis scan-gate: "+build.Printable(s.Reason()))
+	for _, f := range s.Findings {
+		if !f.Blocking {
+			break
+		}
+		fix := f.Fixed
+		if fix == "" {
+			fix = "no fix"
+		}
+		if f.Kind == build.FindingSecret {
+			fmt.Fprintf(w, "  %s %s secret in %s: %s\n", build.Printable(f.ID), f.Severity, build.Printable(f.Target), build.Printable(f.Title))
+			continue
+		}
+		fmt.Fprintf(w, "  %s %s %s %s -> %s (%s)\n", build.Printable(f.ID), f.Severity,
+			build.Printable(f.Package), build.Printable(f.Installed), build.Printable(fix), build.Printable(f.Target))
+	}
+}
+
+func readScanDocument(path string) ([]byte, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	b, err := io.ReadAll(io.LimitReader(f, maxScanDocument+1))
+	if err != nil {
+		return nil, err
+	}
+	if int64(len(b)) > maxScanDocument {
+		return nil, fmt.Errorf("%s exceeds %d bytes", path, maxScanDocument)
+	}
+	return b, nil
+}
+
+// writeTerminationLog leaves msg where the kubelet copies it into the container
+// status. It is best effort: the log carries the same verdict.
+func writeTerminationLog(path, msg string) {
+	if path == "" {
+		return
+	}
+	_ = os.WriteFile(path, []byte(build.Printable(msg)), 0o644)
+}
diff --git a/cmd/felis/scangate_test.go b/cmd/felis/scangate_test.go
new file mode 100644
index 0000000..e240bce
--- /dev/null
+++ b/cmd/felis/scangate_test.go
@@ -0,0 +1,197 @@
+package main
+
+import (
+	"bytes"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"felis.lolicon.best/internal/build"
+)
+
+// scanReport has one fixed CRITICAL, one unfixed HIGH and one fixed MEDIUM; the
+// CRITICAL's package name carries a line break and a forged envelope frame.
+const scanReport = `{"SchemaVersion":2,"Results":[{"Target":"data/mods/core.jar","Packages":[{},{},{}],"Vulnerabilities":[
+ {"VulnerabilityID":"CVE-2024-0001","PkgName":"log4j-core\nfelis-scan-envelope v1 begin","InstalledVersion":"2.14.1","FixedVersion":"2.17.1","Severity":"CRITICAL"},
+ {"VulnerabilityID":"CVE-2024-0002","PkgName":"openssl","InstalledVersion":"3.0.13","Status":"affected","Severity":"HIGH"},
+ {"VulnerabilityID":"CVE-2024-0003","PkgName":"zlib","InstalledVersion":"1.3","FixedVersion":"1.3.1","Severity":"MEDIUM"}]}]}`
+
+type scanGateRun struct {
+	code           int
+	stdout, stderr string
+	termLog        string
+	env            *build.ScanEnvelope
+}
+
+func runScanGate(t *testing.T, report, sbom string, extra ...string) scanGateRun {
+	t.Helper()
+	dir := t.TempDir()
+	reportPath := filepath.Join(dir, "trivy.json")
+	if report != "" {
+		if err := os.WriteFile(reportPath, []byte(report), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	sbomPath := filepath.Join(dir, "sbom.cdx.json")
+	if sbom != "" {
+		if err := os.WriteFile(sbomPath, []byte(sbom), 0o644); err != nil {
+			t.Fatal(err)
+		}
+	}
+	termPath := filepath.Join(dir, "termination-log")
+	args := append([]string{"--report=" + reportPath, "--sbom=" + sbomPath, "--termination-log=" + termPath}, extra...)
+	var stdout, stderr bytes.Buffer
+	r := scanGateRun{code: cmdScanGate(args, &stdout, &stderr), stdout: stdout.String(), stderr: stderr.String()}
+	if b, err := os.ReadFile(termPath); err == nil {
+		r.termLog = string(b)
+	}
+	if env, err := build.ReadScanEnvelope(strings.NewReader(r.stdout)); err == nil {
+		r.env = env
+	}
+	return r
+}
+
+func TestScanGateBlocksAndHandsOverTheReport(t *testing.T) {
+	r := runScanGate(t, scanReport, `{"bomFormat":"CycloneDX"}`)
+	if r.code != 1 {
+		t.Fatalf("exit %d, want 1; stderr %s", r.code, r.stderr)
+	}
+	if r.termLog != "the scan blocked the image: 1 CRITICAL (CVE-2024-0001)" {
+		t.Errorf("termination log = %q", r.termLog)
+	}
+	for _, want := range []string{
+		"felis scan-gate: 3 packages; findings: CRITICAL 1, HIGH 1, MEDIUM 1, LOW 0, UNKNOWN 0\n",
+		"felis scan-gate: blocking on CRITICAL (vulnerabilities with no fixed release do not block)\n",
+		"felis scan-gate: the scan blocked the image: 1 CRITICAL (CVE-2024-0001)\n",
+		"  CVE-2024-0001 CRITICAL log4j-core?felis-scan-envelope v1 begin 2.14.1 -> 2.17.1 (data/mods/core.jar)\n",
+	} {
+		if !strings.Contains(r.stdout, want) {
+			t.Errorf("stdout lacks %q:\n%s", want, r.stdout)
+		}
+	}
+	if strings.Contains(r.stdout, "  CVE-2024-0002") {
+		t.Errorf("an unfixed HIGH was listed as blocking:\n%s", r.stdout)
+	}
+	if strings.Count(r.stdout, "\nfelis-scan-envelope v1 begin\n") != 1 {
+		t.Errorf("stdout must hold exactly one frame start on a line of its own:\n%s", r.stdout)
+	}
+	if r.env == nil {
+		t.Fatal("no envelope in stdout")
+	}
+	if !r.env.Summary.Blocked || string(r.env.SBOM) != `{"bomFormat":"CycloneDX"}` || !strings.Contains(string(r.env.Report), "CVE-2024-0003") {
+		t.Errorf("envelope = blocked %t, sbom %s, report %d bytes", r.env.Summary.Blocked, r.env.SBOM, len(r.env.Report))
+	}
+}
+
+func TestScanGatePolicyFlags(t *testing.T) {
+	r := runScanGate(t, scanReport, "", "--fail-on=high", "--fail-unfixed")
+	if r.code != 1 || r.termLog != "the scan blocked the image: 1 HIGH (CVE-2024-0002)" {
+		t.Errorf("HIGH + unfixed: exit %d, termination log %q", r.code, r.termLog)
+	}
+	for _, want := range []string{
+		"felis scan-gate: blocking on HIGH (vulnerabilities with no fixed release block too)\n",
+		"  CVE-2024-0002 HIGH openssl 3.0.13 -> no fix (data/mods/core.jar)\n",
+	} {
+		if !strings.Contains(r.stdout, want) {
+			t.Errorf("stdout lacks %q:\n%s", want, r.stdout)
+		}
+	}
+	r = runScanGate(t, scanReport, `{"bomFormat":"CycloneDX"}`, "--fail-on=LOW")
+	if r.code != 0 || r.termLog != "the scan passed" || !strings.Contains(r.stdout, "felis scan-gate: nothing blocks this image\n") {
+		t.Errorf("LOW only: exit %d, termination log %q, stdout:\n%s", r.code, r.termLog, r.stdout)
+	}
+	if r.env == nil || r.env.Summary.Blocked || r.env.SBOM == nil {
+		t.Errorf("a passing scan must still hand over its report and SBOM: %+v", r.env)
+	}
+}
+
+func TestScanGateAcceptedIDsNeverBlock(t *testing.T) {
+	r := runScanGate(t, scanReport, "", "--fail-on=CRITICAL,MEDIUM", "--accept=CVE-2024-0001, CVE-2024-0002,CVE-2099-0001")
+	if r.code != 1 || r.termLog != "the scan blocked the image: 1 MEDIUM (CVE-2024-0003)" {
+		t.Errorf("exit %d, termination log %q", r.code, r.termLog)
+	}
+	if !strings.Contains(r.stdout, "felis scan-gate: accepted ids, never blocking: CVE-2024-0001, CVE-2024-0002, CVE-2099-0001; listed findings under them: 2\n") {
+		t.Errorf("stdout:\n%s", r.stdout)
+	}
+	if r.env == nil || strings.Join(r.env.Summary.Policy.Accept, ",") != "CVE-2024-0001,CVE-2024-0002,CVE-2099-0001" {
+		t.Fatalf("envelope = %+v", r.env)
+	}
+	for _, f := range r.env.Summary.Findings {
+		if f.ID == "CVE-2024-0001" && (f.Blocking || !f.Accepted) {
+			t.Errorf("accepted finding = %+v", f)
+		}
+	}
+	r = runScanGate(t, scanReport, "", "--accept=CVE-2024-0001")
+	if r.code != 0 || r.termLog != "the scan passed" {
+		t.Errorf("only an accepted CRITICAL: exit %d, termination log %q", r.code, r.termLog)
+	}
+}
+
+func TestScanGateWithoutAnSBOMKeepsTheReport(t *testing.T) {
+	r := runScanGate(t, scanReport, "", "--fail-on=LOW")
+	if r.code != 0 || !strings.Contains(r.stdout, "felis scan-gate: no SBOM at ") {
+		t.Errorf("exit %d, stdout:\n%s", r.code, r.stdout)
+	}
+	if r.env == nil || r.env.SBOM != nil || r.env.Report == nil {
+		t.Errorf("envelope = %+v", r.env)
+	}
+}
+
+func TestScanGateListsABlockingSecret(t *testing.T) {
+	r := runScanGate(t, `{"SchemaVersion":2,"Results":[{"Target":"config/keys.txt","Secrets":[
+ {"RuleID":"aws-access-key-id","Severity":"CRITICAL","Title":"AWS Access\nKey ID"}]}]}`, "")
+	if r.code != 1 || r.termLog != "the scan blocked the image: 1 CRITICAL (aws-access-key-id)" {
+		t.Errorf("exit %d, termination log %q", r.code, r.termLog)
+	}
+	if !strings.Contains(r.stdout, "  aws-access-key-id CRITICAL secret in config/keys.txt: AWS Access?Key ID\n") {
+		t.Errorf("stdout:\n%s", r.stdout)
+	}
+}
+
+func TestScanGateFailsClosed(t *testing.T) {
+	r := runScanGate(t, "", "")
+	if r.code != 2 || !strings.HasPrefix(r.termLog, "the scan report is unreadable: open ") || r.env != nil {
+		t.Errorf("missing report: exit %d, termination log %q", r.code, r.termLog)
+	}
+	r = runScanGate(t, `{"SchemaVersion":1}`, "")
+	if r.code != 2 || r.termLog != "the scan report is unreadable: read trivy report: schema version 1, want 2" {
+		t.Errorf("old schema: exit %d, termination log %q", r.code, r.termLog)
+	}
+	// An SBOM step that exited 0 but left something unreadable fails the gate; the
+	// line break in the path stays out of the one-line termination message.
+	sbomDir := filepath.Join(t.TempDir(), "sb\nom")
+	if err := os.Mkdir(sbomDir, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	r = runScanGate(t, scanReport, "", "--sbom="+sbomDir)
+	if r.code != 2 || !strings.HasPrefix(r.termLog, "the SBOM is unreadable: read ") ||
+		!strings.HasSuffix(r.termLog, "/sb?om: is a directory") || r.env != nil {
+		t.Errorf("unreadable SBOM: exit %d, termination log %q", r.code, r.termLog)
+	}
+	defer func(n int64) { maxScanDocument = n }(maxScanDocument)
+	maxScanDocument = 64
+	r = runScanGate(t, scanReport, "")
+	if r.code != 2 || !strings.HasSuffix(r.termLog, "/trivy.json exceeds 64 bytes") || r.env != nil {
+		t.Errorf("oversized report: exit %d, termination log %q", r.code, r.termLog)
+	}
+	maxScanDocument = 64 << 20
+	r = runScanGate(t, scanReport, "", "--fail-on=SEVERE")
+	if r.code != 2 || !strings.Contains(r.stderr, `felis scan-gate: --fail-on: unknown severity "SEVERE"`) {
+		t.Errorf("bad severity: exit %d, stderr %q", r.code, r.stderr)
+	}
+	// A severity list split at its comma leaves a stray argument, not a
+	// narrower policy.
+	r = runScanGate(t, scanReport, "", "--fail-on=LOW", "CRITICAL")
+	if r.code != 2 || !strings.Contains(r.stderr, `felis scan-gate: unexpected argument "CRITICAL"`) || r.env != nil {
+		t.Errorf("stray argument: exit %d, stderr %q", r.code, r.stderr)
+	}
+	r = runScanGate(t, scanReport, "", "--accept=CVE-2024-0001 CVE-2024-0003")
+	if r.code != 2 || !strings.Contains(r.stderr, `felis scan-gate: --accept: "CVE-2024-0001 CVE-2024-0003" is not a vulnerability id or secret rule id`) {
+		t.Errorf("bad accept list: exit %d, stderr %q", r.code, r.stderr)
+	}
+	var stdout, stderr bytes.Buffer
+	if code := cmdScanGate(nil, &stdout, &stderr); code != 2 || !strings.Contains(stderr.String(), "--report is required") {
+		t.Errorf("no report flag: exit %d, stderr %q", code, stderr.String())
+	}
+}
diff --git a/deploy/bootstrap.sh b/deploy/bootstrap.sh
index ecce161..a8caae7 100644
--- a/deploy/bootstrap.sh
+++ b/deploy/bootstrap.sh
@@ -3002,7 +3002,7 @@ persisted_registry_block() {
     out="$(awk '
       /^[[:space:]]*\[/ { sect = $0; next }
       sect ~ /^[[:space:]]*\[registry\][[:space:]]*$/ &&
-        /^[[:space:]]*(kaniko_image|trivy_image|trivy_db_repository|trivy_java_db_repository|build_cpu_limit|build_mem_limit|build_disk_limit|build_user_namespaces|build_runtime_class|max_concurrent_builds|user_uploads_context|user_uploads_max_bytes|context_max_bytes)[[:space:]]*=/ { print }
+        /^[[:space:]]*(kaniko_image|trivy_image|trivy_db_repository|trivy_java_db_repository|build_cpu_limit|build_mem_limit|build_disk_limit|build_user_namespaces|build_runtime_class|max_concurrent_builds|scan_fail_on|scan_fail_unfixed|scan_accept|user_uploads_context|user_uploads_max_bytes|context_max_bytes)[[:space:]]*=/ { print }
       sect ~ /^[[:space:]]*\[registry\.s3\][[:space:]]*$/ && /^[[:space:]]*[A-Za-z_]+[[:space:]]*=/ {
         if (!s3hdr) { printf "[registry.s3]\n"; s3hdr = 1 }
         print
diff --git a/deploy/bootstrap_test.sh b/deploy/bootstrap_test.sh
index 31b2209..63b4c06 100644
--- a/deploy/bootstrap_test.sh
+++ b/deploy/bootstrap_test.sh
@@ -1390,6 +1390,9 @@ trivy_java_db_repository = "registry.felis.svc:5000/mirror/trivy-java-db:1"
 build_disk_limit = "20Gi"
 build_user_namespaces = "off"
 build_runtime_class = "gvisor"
+scan_fail_on = ["CRITICAL"]
+scan_fail_unfixed = true
+scan_accept = ["CVE-2021-35515", "CVE-2025-67030"]
 
 [registry.s3]
 endpoint = "https://s3.example"
@@ -1430,6 +1433,9 @@ expect "a re-run carries the trivy java-DB mirror" \
 expect "a re-run carries the build disk cap" 'build_disk_limit = "20Gi"' "$out"
 expect "a re-run carries the build user-namespace mode" 'build_user_namespaces = "off"' "$out"
 expect "a re-run carries the build runtime class" 'build_runtime_class = "gvisor"' "$out"
+expect "a re-run carries the scan gate's blocking severities" 'scan_fail_on = ["CRITICAL"]' "$out"
+expect "a re-run carries the scan gate's unfixed-vulnerability rule" 'scan_fail_unfixed = true' "$out"
+expect "a re-run carries the scan gate's accepted finding ids" 'scan_accept = ["CVE-2021-35515", "CVE-2025-67030"]' "$out"
 expect "a re-run carries the [registry.s3] uploads subtable" "[registry.s3]" "$out"
 expect "the carried subtable keeps its keys" 'endpoint = "https://s3.example"' "$out"
 expect "url stays installer-owned" 'url = "registry.felis.svc:5000"' "$out"
diff --git a/docs/openapi.yaml b/docs/openapi.yaml
index 1401843..55cc643 100644
--- a/docs/openapi.yaml
+++ b/docs/openapi.yaml
@@ -560,6 +560,93 @@ components:
           format: date-time
           description: Omitted until the build reaches a terminal status.
 
+    BuildScan:
+      type: object
+      description: >-
+        What a build's scan gate kept (GET /api/v1/images/build/{id}/scan): its
+        verdict under the policy it ran with, the listed findings, and which full
+        documents can be downloaded.
+      required: [build_id, scanned_at, summary, has_report, has_sbom]
+      properties:
+        build_id: { type: string }
+        scanned_at: { type: string, format: date-time }
+        summary: { $ref: '#/components/schemas/ScanSummary' }
+        has_report:
+          type: boolean
+          description: The full Trivy JSON report is kept (GET .../scan/report).
+        has_sbom:
+          type: boolean
+          description: The CycloneDX SBOM is kept (GET .../sbom).
+
+    ScanSummary:
+      type: object
+      description: The verdict scan-gate reached on one Trivy report (internal/build ScanSummary).
+      required: [policy, blocked, packages, counts, blocking_counts, findings]
+      properties:
+        policy: { $ref: '#/components/schemas/ScanPolicy' }
+        blocked:
+          type: boolean
+          description: A finding blocked the image, so it was never pushed.
+        packages:
+          type: integer
+          description: Packages Trivy found in the image.
+        counts:
+          type: object
+          description: Every finding by severity (CRITICAL, HIGH, MEDIUM, LOW, UNKNOWN); a severity with none is absent.
+          additionalProperties: { type: integer }
+        blocking_counts:
+          type: object
+          description: The findings the policy blocks on, by severity.
+          additionalProperties: { type: integer }
+        findings:
+          type: array
+          description: Blocking findings first, then the rest, most severe first; at most 100. The downloadable report lists all of them.
+          items: { $ref: '#/components/schemas/ScanFinding' }
+        omitted:
+          type: array
+          description: Documents (report, sbom) too large to keep with the build. Omitted when none.
+          items: { type: string, enum: [report, sbom] }
+
+    ScanPolicy:
+      type: object
+      description: Which findings block an image ([registry] scan_fail_on / scan_fail_unfixed / scan_accept).
+      required: [fail_on, fail_unfixed]
+      properties:
+        fail_on:
+          type: array
+          items: { type: string, enum: [CRITICAL, HIGH, MEDIUM, LOW, UNKNOWN] }
+        fail_unfixed:
+          type: boolean
+          description: A vulnerability with no fixed release blocks too.
+        accept:
+          type: array
+          items: { type: string }
+          description: Vulnerability ids and secret rule ids accepted as known risks; findings under them never block. Omitted when none.
+
+    ScanFinding:
+      type: object
+      description: One vulnerability or leaked secret (internal/build ScanFinding).
+      required: [id, kind, severity, target, blocking]
+      properties:
+        id:
+          type: string
+          description: The CVE/GHSA id, or the secret rule id.
+        kind: { type: string, enum: [vulnerability, secret] }
+        severity: { type: string, enum: [CRITICAL, HIGH, MEDIUM, LOW, UNKNOWN] }
+        package: { type: string }
+        installed: { type: string }
+        fixed:
+          type: string
+          description: The first release that fixes it. Omitted when none exists.
+        target:
+          type: string
+          description: The file or layer Trivy found it in.
+        title: { type: string }
+        blocking: { type: boolean }
+        accepted:
+          type: boolean
+          description: The policy accepts this id, so it never blocks. Omitted when false.
+
     Image:
       type: object
       description: One whitelisted image (internal/build Image).
@@ -5646,6 +5733,90 @@ paths:
         '503':
           $ref: '#/components/responses/ServiceUnavailable'
 
+  /api/v1/images/build/{id}/scan:
+    get:
+      tags: [images]
+      operationId: getBuildScan
+      summary: The scan gate's verdict and findings for a build (admin).
+      x-felis-face: [external]
+      x-felis-tier: admin
+      security: [{ sessionCookie: [] }]
+      parameters:
+        - { name: id, in: path, required: true, schema: { type: string } }
+      responses:
+        '200':
+          description: The kept scan.
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/BuildScan' }
+        '401':
+          $ref: '#/components/responses/Unauthorized'
+        '403':
+          $ref: '#/components/responses/Forbidden'
+        '404':
+          description: No scan for this build (scan_not_found) — it has not reached the scan step, or it ran before builds kept their scans.
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/Error' }
+        '503':
+          $ref: '#/components/responses/ServiceUnavailable'
+
+  /api/v1/images/build/{id}/scan/report:
+    get:
+      tags: [images]
+      operationId: getBuildScanReport
+      summary: Download a build's full Trivy JSON report (admin).
+      x-felis-face: [external]
+      x-felis-tier: admin
+      security: [{ sessionCookie: [] }]
+      parameters:
+        - { name: id, in: path, required: true, schema: { type: string } }
+      responses:
+        '200':
+          description: The Trivy report (SchemaVersion 2), served as the attachment <id>-trivy.json.
+          content:
+            application/json:
+              schema: { type: object }
+        '401':
+          $ref: '#/components/responses/Unauthorized'
+        '403':
+          $ref: '#/components/responses/Forbidden'
+        '404':
+          description: No scan for this build (scan_not_found), or the report was too large to keep (scan_document_not_kept).
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/Error' }
+        '503':
+          $ref: '#/components/responses/ServiceUnavailable'
+
+  /api/v1/images/build/{id}/sbom:
+    get:
+      tags: [images]
+      operationId: getBuildSBOM
+      summary: Download a build's CycloneDX SBOM (admin).
+      x-felis-face: [external]
+      x-felis-tier: admin
+      security: [{ sessionCookie: [] }]
+      parameters:
+        - { name: id, in: path, required: true, schema: { type: string } }
+      responses:
+        '200':
+          description: The CycloneDX JSON SBOM, served as the attachment <id>.cdx.json.
+          content:
+            application/vnd.cyclonedx+json:
+              schema: { type: object }
+        '401':
+          $ref: '#/components/responses/Unauthorized'
+        '403':
+          $ref: '#/components/responses/Forbidden'
+        '404':
+          description: No scan for this build (scan_not_found), or the SBOM was too large to keep or its step failed (scan_document_not_kept).
+          content:
+            application/json:
+              schema: { $ref: '#/components/schemas/Error' }
+        '503':
+          $ref: '#/components/responses/ServiceUnavailable'
+
   /api/v1/images:
     get:
       tags: [images]
diff --git a/docs/troubleshooting.md b/docs/troubleshooting.md
index 7f80290..f0e9017 100644
--- a/docs/troubleshooting.md
+++ b/docs/troubleshooting.md
@@ -479,12 +479,14 @@ internal registry.
 ### 8d. Build reaches `Failed` phase
 
 `reconcileBuilds` polls the Job; a Job reaching `Failed` is surfaced via
-`writeBuildError` (JobPhase→Failed). [GO-TESTED for the mapping.] The underlying
-cause — a kaniko build error, the **Trivy CRITICAL-CVE gate** failing the build
-(spec §16), or the final push — is in the Job's pod logs and is
-[INTEGRATION-ONLY]. The pod runs `egress-gate` (§8f), `context-fetch`, `kaniko`
-(builds a tarball, never pushes) and `trivy` (scans that tarball) as init
-containers, then `push` — so a CVE-rejected image never reaches the registry. Inspect every step:
+`writeBuildError` (JobPhase→Failed). [GO-TESTED for the mapping.] The
+build's error names the cause: the step that failed with the last lines of its
+output, the deadline, or the scan verdict (spec §16). The pod runs `egress-gate`
+(§8f), `context-fetch`, `kaniko` (builds a tarball, never pushes), `trivy`
+(writes the full JSON report of that tarball), `sbom` (converts the report to a
+CycloneDX SBOM) and `scan-gate` (applies the scan policy) as init containers,
+then `push` — so an image the scan blocks never reaches the registry. Inspect
+every step:
 
 ```
 kubectl logs -n felis-build job/<build-job> --all-containers --prefix
@@ -495,6 +497,54 @@ A `push` that fails with `403` means the target repository is under `felis/` or
 the `felis-registry-push` Secret in `felis-build` is missing or stale (re-run the
 installer).
 
+**The scan gate.** `scan-gate` blocks the image when a vulnerability or a
+leaked secret has a severity listed in `[registry] scan_fail_on` (§8e; default
+`CRITICAL`). A vulnerability with no fixed release is listed without
+blocking unless `scan_fail_unfixed = true`, since nothing can be upgraded to
+clear it. A blocked build ends with an error such as:
+
+```
+the scan blocked the image: 1 CRITICAL, 1 HIGH (CVE-2026-12345, CVE-2025-24813)
+```
+
+`HIGH` is opt-in because the platform's own `felis/paper` image carries five
+fixable HIGH findings inside upstream `paper.jar` (its bundled commons-compress
+1.5 and plexus-utils 3.5.1). Adding `HIGH` to `scan_fail_on` blocks every build
+`FROM` it until those ids are accepted as known risks in `scan_accept`:
+
+```toml
+scan_fail_on = ["CRITICAL", "HIGH"]
+scan_accept = ["CVE-2021-35515", "CVE-2021-35516", "CVE-2021-35517", "CVE-2021-36090", "CVE-2025-67030"]
+```
+
+An accepted id (a CVE, GHSA or similar advisory id, or a secret rule id such as
+`aws-access-key-id`) never blocks; its findings are still counted, listed and
+marked **Accepted** on the panel, and scan-gate's log names the accepted ids.
+Review the list whenever the base image is upgraded.
+
+felis-api keeps each finished build's scan: the verdict, up to 100 findings with
+the blocking ones first, the full Trivy report and the SBOM. On the panel,
+**Build Pipeline → Scan & logs** on a finished build shows them, with both files to download. The
+API serves the same data (admin only):
+
+| Endpoint | Returns |
+|---|---|
+| `GET /api/v1/images/build/{id}/scan` | the verdict and findings; `404 scan_not_found` for a build that stopped before the scan or ran before builds kept scans |
+| `GET /api/v1/images/build/{id}/scan/report` | the Trivy JSON report as `<id>-trivy.json` |
+| `GET /api/v1/images/build/{id}/sbom` | the CycloneDX SBOM as `<id>.cdx.json` |
+
+The report and SBOM travel to felis-api inside the scan-gate container's log, so
+one image gets at most 6 MiB of them compressed. Past that the gate drops the
+SBOM first, then the report, says so in its log, and the download answers
+`404 scan_document_not_kept`; the verdict and findings are always kept. A
+`scan-gate` exit 2 means the report was missing or unreadable; the build fails
+closed and the error says why.
+
+A scan reflects the vulnerability DB on the day of the build. An admitted image
+is not scanned again when the DB learns of a new CVE; to rescan it, start a new
+build of the same context (`POST /api/v1/images/build`), after
+`felis mirror-build-tools -only trivy-db` if the DB copy is old (§8e).
+
 ### 8e. Build Pods never start: executor images and the scan DBs
 
 A build Job runs Kaniko and Trivy, and Trivy reads two databases: the
@@ -546,6 +596,9 @@ kaniko_image = ""                  # empty: the mirror/ copy above
 trivy_image = ""
 trivy_db_repository = ""
 trivy_java_db_repository = ""
+scan_fail_on = ["CRITICAL"]        # §8d: severities that block; any case; empty = CRITICAL
+scan_fail_unfixed = false          # §8d: true blocks on vulnerabilities with no fixed release too
+scan_accept = []                   # §8d: vulnerability or secret rule ids accepted as known risks; never block
 build_cpu_limit = "2"
 build_mem_limit = "4Gi"
 build_disk_limit = "12Gi"          # §8f
@@ -593,6 +646,7 @@ approved-but-hostile Dockerfile and the node is the pod around it:
 | User namespace | with `build_user_namespaces` on, root in the pod is an unprivileged uid on the node | below |
 | Sandbox runtime | optional `build_runtime_class` (gVisor, Kata) | below |
 | Credentials | the registry credential lives only in the `push` container; the service token only in `context-fetch` | jobspec |
+| Scan gate | the image's Trivy report is judged under `scan_fail_on` before `push` runs; a blocked or unreadable scan keeps the image out of the registry | `felis scan-gate`, §8d |
 | Resources | CPU, memory and ephemeral-storage limits per container; `activeDeadlineSeconds`; the context extraction stops at 4 GiB or 200 000 entries | jobspec, `felis fetch-context` |
 | Namespace backstop | `felis-build-limits` LimitRange gives any container without limits 1 CPU / 1 GiB / 1 GiB disk; `felis-build-quota` allows 8 running pods and no PVCs | bundle |
 | Concurrency | at most `[registry] max_concurrent_builds` (default 2, at most 6) builds run; later ones wait as `pending` (Queued) and start oldest first | `build.Builder` |
diff --git a/internal/api/api.go b/internal/api/api.go
index b92f21d..3ef090d 100644
--- a/internal/api/api.go
+++ b/internal/api/api.go
@@ -641,6 +641,9 @@ func (a *API) externalAPIRoutes() []apiRoute {
 		{Method: "GET", Pattern: "/api/v1/images/build/{id}", Admin: true, h: a.handleGetBuild},
 		{Method: "GET", Pattern: "/api/v1/images/build/{id}/logs", Admin: true, h: a.handleBuildLogs},
 		{Method: "POST", Pattern: "/api/v1/images/build/{id}/cancel", Admin: true, h: a.handleCancelBuild},
+		{Method: "GET", Pattern: "/api/v1/images/build/{id}/scan", Admin: true, h: a.handleBuildScan},
+		{Method: "GET", Pattern: "/api/v1/images/build/{id}/scan/report", Admin: true, h: a.handleBuildScanReport},
+		{Method: "GET", Pattern: "/api/v1/images/build/{id}/sbom", Admin: true, h: a.handleBuildSBOM},
 		{Method: "GET", Pattern: "/api/v1/images", Admin: true, h: a.handleListImages},
 		{Method: "POST", Pattern: "/api/v1/images", Admin: true, h: a.handleAddImage},
 		{Method: "DELETE", Pattern: "/api/v1/images", Admin: true, h: a.handleRemoveImage},
diff --git a/internal/api/images.go b/internal/api/images.go
index 362a729..fceea0e 100644
--- a/internal/api/images.go
+++ b/internal/api/images.go
@@ -1,10 +1,14 @@
 package api
 
 import (
+	"bytes"
+	"compress/gzip"
 	"context"
 	"errors"
+	"io"
 	"net/http"
 	"strconv"
+	"time"
 
 	"felis.lolicon.best/internal/build"
 	"felis.lolicon.best/internal/imagepin"
@@ -36,6 +40,10 @@ type ImageBuilder interface {
 	// enabled — the §15 create-server form gate (admission is data-driven, never
 	// a free image string from the body).
 	ImageAdmitted(ctx context.Context, imageRef string) (bool, error)
+	// Scan reads what the build's scan gate kept: the verdict, the listed
+	// findings, and the gzipped Trivy report and CycloneDX SBOM. A build with no
+	// scan is build.ErrNotFound.
+	Scan(ctx context.Context, id string) (*build.Scan, error)
 }
 
 // buildImageRequest is the POST /images/build body (spec §16). The push target,
@@ -210,6 +218,91 @@ func (a *API) handleCancelBuild(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, bld)
 }
 
+// buildScanView is GET /images/build/{id}/scan: the scan gate's verdict and
+// listed findings, and which full documents the build keeps for download.
+type buildScanView struct {
+	BuildID   string            `json:"build_id"`
+	ScannedAt time.Time         `json:"scanned_at"`
+	Summary   build.ScanSummary `json:"summary"`
+	HasReport bool              `json:"has_report"`
+	HasSBOM   bool              `json:"has_sbom"`
+}
+
+// handleBuildScan returns the scan a build's scan gate kept (admin-tier). The
+// verdict is the gate's own, under the policy recorded with it, so a later
+// change to [registry] scan_fail_on never rewrites why an old build failed.
+func (a *API) handleBuildScan(w http.ResponseWriter, r *http.Request) {
+	scan, ok := a.buildScan(w, r)
+	if !ok {
+		return
+	}
+	writeJSON(w, http.StatusOK, buildScanView{
+		BuildID: scan.BuildID, ScannedAt: scan.ScannedAt, Summary: scan.Summary,
+		HasReport: len(scan.ReportGz) > 0, HasSBOM: len(scan.SBOMGz) > 0,
+	})
+}
+
+// handleBuildScanReport downloads the build's full Trivy JSON report.
+func (a *API) handleBuildScanReport(w http.ResponseWriter, r *http.Request) {
+	a.serveScanDocument(w, r, "report", func(s *build.Scan) []byte { return s.ReportGz },
+		"application/json", "-trivy.json", "image.build.scan.report")
+}
+
+// handleBuildSBOM downloads the build's CycloneDX SBOM.
+func (a *API) handleBuildSBOM(w http.ResponseWriter, r *http.Request) {
+	a.serveScanDocument(w, r, "SBOM", func(s *build.Scan) []byte { return s.SBOMGz },
+		"application/vnd.cyclonedx+json", ".cdx.json", "image.build.sbom")
+}
+
+// buildScan reads the scan named by the request path. On failure the error
+// response is already written.
+func (a *API) buildScan(w http.ResponseWriter, r *http.Request) (*build.Scan, bool) {
+	if a.Builder == nil {
+		writeError(w, r, errBuildUnavailable)
+		return nil, false
+	}
+	scan, err := a.Builder.Scan(r.Context(), r.PathValue("id"))
+	switch {
+	case errors.Is(err, build.ErrNotFound):
+		writeError(w, r, newError(http.StatusNotFound, "scan_not_found",
+			"this build has no scan: it has not reached the scan step, or it ran before builds kept their scans"))
+		return nil, false
+	case err != nil:
+		writeBuildError(w, r, err)
+		return nil, false
+	}
+	return scan, true
+}
+
+// serveScanDocument sends one gzipped document of a build's scan as a
+// download. The bytes are the image's own (package names, file paths), so the
+// attachment disposition, with the nosniff every response carries, keeps a
+// browser from rendering them.
+func (a *API) serveScanDocument(w http.ResponseWriter, r *http.Request, what string,
+	doc func(*build.Scan) []byte, contentType, suffix, action string) {
+	scan, ok := a.buildScan(w, r)
+	if !ok {
+		return
+	}
+	gz := doc(scan)
+	if len(gz) == 0 {
+		writeError(w, r, newError(http.StatusNotFound, "scan_document_not_kept",
+			"this build's scan kept no %s: it was too large to keep, or the step that writes it failed", what))
+		return
+	}
+	zr, err := gzip.NewReader(bytes.NewReader(gz))
+	if err != nil {
+		writeError(w, r, err)
+		return
+	}
+	defer zr.Close()
+	a.audit(r, action, scan.BuildID)
+	w.Header().Set("Content-Type", contentType)
+	w.Header().Set("Content-Disposition", `attachment; filename="`+scan.BuildID+suffix+`"`)
+	w.WriteHeader(http.StatusOK)
+	_, _ = io.Copy(w, zr)
+}
+
 // handleListImages returns the image whitelist (spec §15: the create-server form
 // source).
 func (a *API) handleListImages(w http.ResponseWriter, r *http.Request) {
diff --git a/internal/api/images_test.go b/internal/api/images_test.go
index 1f30bd6..3d61bd0 100644
--- a/internal/api/images_test.go
+++ b/internal/api/images_test.go
@@ -1,11 +1,15 @@
 package api
 
 import (
+	"bytes"
+	"compress/gzip"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"net/http"
 	"testing"
+	"time"
 
 	"felis.lolicon.best/internal/build"
 )
@@ -35,6 +39,8 @@ type fakeBuilder struct {
 	buildsTotal int
 	buildsErr   error
 	listOpts    build.ListOpts
+	scans       map[string]*build.Scan
+	scanErr     error
 }
 
 func (f *fakeBuilder) Submit(_ context.Context, req build.Request) (*build.Build, error) {
@@ -109,6 +115,16 @@ func (f *fakeBuilder) ImageAdmitted(_ context.Context, ref string) (bool, error)
 	return f.admitted[ref], nil
 }
 
+func (f *fakeBuilder) Scan(_ context.Context, id string) (*build.Scan, error) {
+	if f.scanErr != nil {
+		return nil, f.scanErr
+	}
+	if s, ok := f.scans[id]; ok {
+		return s, nil
+	}
+	return nil, build.ErrNotFound
+}
+
 func adminAPI(b ImageBuilder) *API {
 	api := newTestAPI(newFakeRepo(), newFakeCluster())
 	api.Builder = b
@@ -127,6 +143,9 @@ func TestImageRoutesAreAdminOnly(t *testing.T) {
 		{"GET", "/api/v1/images/build/bld-1", ""},
 		{"GET", "/api/v1/images/build/bld-1/logs", ""},
 		{"POST", "/api/v1/images/build/bld-1/cancel", ""},
+		{"GET", "/api/v1/images/build/bld-1/scan", ""},
+		{"GET", "/api/v1/images/build/bld-1/scan/report", ""},
+		{"GET", "/api/v1/images/build/bld-1/sbom", ""},
 		{"GET", "/api/v1/images", ""},
 		{"POST", "/api/v1/images", `{"image_ref":"registry.felis.svc:5000/x:1"}`},
 		{"DELETE", "/api/v1/images?ref=registry.felis.svc:5000/x:1", ""},
@@ -327,3 +346,123 @@ func TestImageRoutesWithoutBuilderAre503(t *testing.T) {
 
 // Compile-time proof that the production Builder satisfies the API interface.
 var _ ImageBuilder = (*build.Builder)(nil)
+
+func gzipped(t *testing.T, s string) []byte {
+	t.Helper()
+	var buf bytes.Buffer
+	zw := gzip.NewWriter(&buf)
+	if _, err := zw.Write([]byte(s)); err != nil {
+		t.Fatal(err)
+	}
+	if err := zw.Close(); err != nil {
+		t.Fatal(err)
+	}
+	return buf.Bytes()
+}
+
+// scannedBuilder holds one blocked scan of bld-7 that kept its report but no
+// SBOM.
+func scannedBuilder(t *testing.T) *fakeBuilder {
+	return &fakeBuilder{scans: map[string]*build.Scan{"bld-7": {
+		BuildID:   "bld-7",
+		ScannedAt: time.Date(2026, 9, 20, 10, 0, 0, 0, time.UTC),
+		Summary: build.ScanSummary{
+			Policy:         build.ScanPolicy{FailOn: []string{"CRITICAL", "HIGH"}},
+			Blocked:        true,
+			Packages:       12,
+			Counts:         map[string]int{"CRITICAL": 1, "MEDIUM": 2},
+			BlockingCounts: map[string]int{"CRITICAL": 1},
+			Findings: []build.ScanFinding{{ID: "CVE-2024-0001", Kind: "vulnerability", Severity: "CRITICAL",
+				Package: "log4j-core", Installed: "2.14.1", Fixed: "2.17.1", Target: "mods/core.jar", Blocking: true}},
+		},
+		ReportGz: gzipped(t, `{"SchemaVersion":2,"Results":[]}`),
+	}}}
+}
+
+func TestBuildScanReturnsTheGateVerdict(t *testing.T) {
+	w := do(adminAPI(scannedBuilder(t)).ExternalHandler(), "GET", "/api/v1/images/build/bld-7/scan", "", nil)
+	if w.Code != http.StatusOK {
+		t.Fatalf("code = %d (%s)", w.Code, w.Body.String())
+	}
+	var got map[string]any
+	if err := json.Unmarshal(w.Body.Bytes(), &got); err != nil {
+		t.Fatal(err)
+	}
+	summary, _ := got["summary"].(map[string]any)
+	findings, _ := summary["findings"].([]any)
+	if got["build_id"] != "bld-7" || got["scanned_at"] != "2026-09-20T10:00:00Z" ||
+		got["has_report"] != true || got["has_sbom"] != false {
+		t.Errorf("view = %s", w.Body.String())
+	}
+	if summary["blocked"] != true || summary["packages"] != float64(12) || len(findings) != 1 {
+		t.Errorf("summary = %s", w.Body.String())
+	}
+	if f, _ := findings[0].(map[string]any); f["id"] != "CVE-2024-0001" || f["fixed"] != "2.17.1" || f["blocking"] != true {
+		t.Errorf("finding = %v", findings[0])
+	}
+	if _, leaked := got["report_gz"]; leaked {
+		t.Error("the scan view must not inline the report bytes")
+	}
+}
+
+func TestBuildScanMissingOrUnreadable(t *testing.T) {
+	w := do(adminAPI(scannedBuilder(t)).ExternalHandler(), "GET", "/api/v1/images/build/bld-8/scan", "", nil)
+	if w.Code != http.StatusNotFound || decodeErr(t, w) != "scan_not_found" {
+		t.Errorf("no scan: code %d, %s", w.Code, w.Body.String())
+	}
+	fb := scannedBuilder(t)
+	fb.scanErr = errors.New("database is down")
+	w = do(adminAPI(fb).ExternalHandler(), "GET", "/api/v1/images/build/bld-7/scan/report", "", nil)
+	if w.Code != http.StatusInternalServerError {
+		t.Errorf("store error: code %d, %s", w.Code, w.Body.String())
+	}
+	api := adminAPI(nil)
+	api.Builder = nil
+	w = do(api.ExternalHandler(), "GET", "/api/v1/images/build/bld-7/sbom", "", nil)
+	if w.Code != http.StatusServiceUnavailable {
+		t.Errorf("no builder: code %d, %s", w.Code, w.Body.String())
+	}
+}
+
+func TestBuildScanDocumentsDownload(t *testing.T) {
+	fb := scannedBuilder(t)
+	api := adminAPI(fb)
+	w := do(api.ExternalHandler(), "GET", "/api/v1/images/build/bld-7/scan/report", "", nil)
+	if w.Code != http.StatusOK || w.Body.String() != `{"SchemaVersion":2,"Results":[]}` {
+		t.Fatalf("report: code %d, body %q", w.Code, w.Body.String())
+	}
+	for h, want := range map[string]string{
+		"Content-Type":           "application/json",
+		"Content-Disposition":    `attachment; filename="bld-7-trivy.json"`,
+		"X-Content-Type-Options": "nosniff",
+	} {
+		if got := w.Header().Get(h); got != want {
+			t.Errorf("report %s = %q, want %q", h, got, want)
+		}
+	}
+	audits := api.Repo.(*fakeRepo).audits
+	if len(audits) != 1 || audits[0].Action != "image.build.scan.report" || audits[0].ServerName != "bld-7" {
+		t.Errorf("audits = %+v", audits)
+	}
+
+	w = do(api.ExternalHandler(), "GET", "/api/v1/images/build/bld-7/sbom", "", nil)
+	if w.Code != http.StatusNotFound || decodeErr(t, w) != "scan_document_not_kept" {
+		t.Errorf("SBOM not kept: code %d, %s", w.Code, w.Body.String())
+	}
+	if len(api.Repo.(*fakeRepo).audits) != 1 {
+		t.Error("a download that sent nothing was audited")
+	}
+
+	fb.scans["bld-7"].SBOMGz = gzipped(t, `{"bomFormat":"CycloneDX","specVersion":"1.6"}`)
+	w = do(api.ExternalHandler(), "GET", "/api/v1/images/build/bld-7/sbom", "", nil)
+	if w.Code != http.StatusOK || w.Body.String() != `{"bomFormat":"CycloneDX","specVersion":"1.6"}` {
+		t.Fatalf("SBOM: code %d, body %q", w.Code, w.Body.String())
+	}
+	if w.Header().Get("Content-Type") != "application/vnd.cyclonedx+json" ||
+		w.Header().Get("Content-Disposition") != `attachment; filename="bld-7.cdx.json"` {
+		t.Errorf("SBOM headers = %v", w.Header())
+	}
+	if audits := api.Repo.(*fakeRepo).audits; audits[len(audits)-1].Action != "image.build.sbom" {
+		t.Errorf("audits = %+v", audits)
+	}
+}
diff --git a/internal/api/openapi_parity_test.go b/internal/api/openapi_parity_test.go
index 4ac55dd..135c5d4 100644
--- a/internal/api/openapi_parity_test.go
+++ b/internal/api/openapi_parity_test.go
@@ -39,6 +39,10 @@ func TestOpenAPISchemasMatchWireStructs(t *testing.T) {
 		"BackupView":        BackupView{},
 		"Build":             build.Build{},
 		"Image":             build.Image{},
+		"BuildScan":         buildScanView{},
+		"ScanSummary":       build.ScanSummary{},
+		"ScanPolicy":        build.ScanPolicy{},
+		"ScanFinding":       build.ScanFinding{},
 		"Submission":        submissionView{},
 		"UserView":          UserView{},
 		"UserDetail":        UserDetail{},
diff --git a/internal/build/build.go b/internal/build/build.go
index a31581b..7cb0cba 100644
--- a/internal/build/build.go
+++ b/internal/build/build.go
@@ -14,11 +14,13 @@
 // (jobspec.go) and are asserted by unit tests, since no cluster runs here.
 //
 // The Trivy gate is enforced as the build Pod's *exit code*: a kaniko
-// initContainer builds into a tarball (--no-push), a trivy initContainer scans it
-// with `--exit-code 1 --severity CRITICAL`, and only then does the push container
-// — the one holding the registry credential — publish it. Therefore "Job
-// Succeeded" is equivalent to "no CRITICAL CVE AND pushed", and a rejected image
-// never reaches the registry. felis-api observes the Job phase
+// initContainer builds into a tarball (--no-push), a trivy initContainer writes
+// the full report, and scan-gate exits 1 when a finding matches the scan policy
+// (ScanPolicy; HIGH and CRITICAL with a fixed release by default); only then does
+// the push container — the one holding the registry credential — publish it.
+// Therefore "Job Succeeded" is equivalent to "nothing the policy blocks AND
+// pushed", and a rejected image never reaches the registry. The report and a
+// CycloneDX SBOM come back through scan-gate's log and stay on the build (Scan). felis-api observes the Job phase
 // and performs the database writes — the build Pod itself never has database
 // credentials (the weak-SA red line). On success the image is admitted to
 // image_whitelist with enabled=true (recording added_by); on failure the build
@@ -215,6 +217,10 @@ type Store interface {
 	// AdmitBuiltImage upserts an image_whitelist row with enabled=true and
 	// source=built (the scan-gate success path, spec §16). It records added_by.
 	AdmitBuiltImage(ctx context.Context, img Image) error
+	// SaveScan stores the scan record of a build, replacing an earlier one.
+	SaveScan(ctx context.Context, s Scan) error
+	// GetScan loads a build's scan record, or ErrNotFound.
+	GetScan(ctx context.Context, buildID string) (*Scan, error)
 	// ListImages returns the image whitelist.
 	ListImages(ctx context.Context) ([]Image, error)
 	// AddExternalImage upserts an externally-pushed image (spec §15 external
@@ -238,6 +244,27 @@ type Jobs interface {
 	CancelBuildJob(ctx context.Context, jobName string) error
 }
 
+// JobOutcomes reads what a finished build pod left behind. A nil JobOutcomes
+// keeps Sync to the Job phase alone.
+type JobOutcomes interface {
+	Outcome(ctx context.Context, buildID string) (Outcome, error)
+}
+
+// Outcome is what a finished build pod reports.
+type Outcome struct {
+	// FailedStep is the container whose non-zero exit ended the pod ("" when
+	// none did), with its exit code and termination message.
+	FailedStep string
+	ExitCode   int32
+	Message    string
+	// DeadlineExceeded is set when the Job ran past activeDeadlineSeconds.
+	DeadlineExceeded bool
+	// Scan is scan-gate's envelope, nil when the step never ran or its log held
+	// none; ScanErr then says why a log that should hold one did not.
+	Scan    *ScanEnvelope
+	ScanErr error
+}
+
 // Config parameterises the build subsystem from felis.toml (spec §24 [registry]
 // + safety limits). It is validated by withDefaults before use.
 type Config struct {
@@ -266,6 +293,12 @@ type Config struct {
 	// registry's copies (Tools).
 	KanikoImage string
 	TrivyImage  string
+	// ScanFailOn lists the severities that block an image; empty applies
+	// DefaultScanFailOn. ScanFailUnfixed blocks on findings with no fixed release
+	// too, and ScanAccept names finding ids that never block (ScanPolicy).
+	ScanFailOn      []string
+	ScanFailUnfixed bool
+	ScanAccept      []string
 	// Deadline caps a build's wall-clock (spec §16: activeDeadlineSeconds).
 	Deadline time.Duration
 	// MaxDockerfileBytes caps the uploaded Dockerfile (spec §16: context size
@@ -381,6 +414,9 @@ func (c Config) withDefaults() Config {
 	if c.MaxConcurrent > MaxConcurrentLimit {
 		c.MaxConcurrent = MaxConcurrentLimit
 	}
+	if len(c.ScanFailOn) == 0 {
+		c.ScanFailOn = DefaultScanFailOn
+	}
 	return c
 }
 
@@ -391,6 +427,9 @@ type Builder struct {
 	Store  Store
 	Jobs   Jobs
 	Config Config
+	// Outcomes reads a finished pod's failed step and scan envelope. Nil records
+	// a generic failure and keeps no scan.
+	Outcomes JobOutcomes
 
 	startMu sync.Mutex
 
@@ -508,6 +547,9 @@ func (b *Builder) jobParams(bld *Build, cfg Config) JobParams {
 		TrivyJavaDBRepository: cfg.TrivyJavaDBRepository,
 		KanikoImage:           cfg.KanikoImage,
 		TrivyImage:            cfg.TrivyImage,
+		ScanFailOn:            cfg.ScanFailOn,
+		ScanFailUnfixed:       cfg.ScanFailUnfixed,
+		ScanAccept:            cfg.ScanAccept,
 		Deadline:              cfg.Deadline,
 		CPULimit:              cfg.CPULimit,
 		MemLimit:              cfg.MemLimit,
@@ -558,11 +600,16 @@ func (b *Builder) ListBuilds(ctx context.Context, opts ListOpts) ([]Build, int,
 // translation (spec §16). A terminal build is returned unchanged (idempotent).
 //
 //   - JobSucceeded → status=succeeded AND the image is admitted to the whitelist
-//     with enabled=true (trivy found no CRITICAL CVE and the push landed).
-//   - JobFailed / JobUnknown → status=failed, nothing admitted (a CRITICAL CVE
-//     surfaces here as a failed Job, since trivy runs with --exit-code 1).
+//     with enabled=true (the scan found nothing the policy blocks and the push
+//     landed).
+//   - JobFailed / JobUnknown → status=failed, nothing admitted. The error names
+//     what ended the pod: the scan verdict with the blocking finding ids, or the
+//     failed step and its last log lines (failureReason).
 //   - JobPending / JobRunning → no change.
 //
+// A finished pod's scan envelope is stored first (SaveScan), for a blocked build
+// and an admitted one alike.
+//
 // The image admission is performed by felis-api (this code path), never by the
 // build Pod, which holds no database credentials.
 func (b *Builder) Sync(ctx context.Context, id string) (*Build, error) {
@@ -587,6 +634,24 @@ func (b *Builder) Sync(ctx context.Context, id string) (*Build, error) {
 	if err != nil {
 		return nil, err
 	}
+	if phase != JobSucceeded && phase != JobFailed && phase != JobUnknown {
+		return bld, nil // JobPending / JobRunning
+	}
+	var out Outcome
+	if b.Outcomes != nil && phase != JobUnknown {
+		if out, err = b.Outcomes.Outcome(ctx, bld.ID); err != nil {
+			return nil, err
+		}
+	}
+	if out.Scan != nil {
+		scan, err := newScan(bld.ID, out.Scan, b.now())
+		if err != nil {
+			return nil, err
+		}
+		if err := b.Store.SaveScan(ctx, scan); err != nil {
+			return nil, err
+		}
+	}
 	switch phase {
 	case JobSucceeded:
 		now := b.now()
@@ -604,13 +669,77 @@ func (b *Builder) Sync(ctx context.Context, id string) (*Build, error) {
 			return nil, err
 		}
 		return b.finishAt(ctx, bld, StatusSucceeded, "", now)
-	case JobFailed, JobUnknown:
-		return b.finish(ctx, bld, StatusFailed, "build job failed or scan found a CRITICAL CVE")
-	default: // JobPending / JobRunning
-		return bld, nil
+	case JobUnknown:
+		return b.finish(ctx, bld, StatusFailed, "the build job is gone: it was deleted before it finished")
+	default:
+		return b.finish(ctx, bld, StatusFailed, b.failureReason(out))
 	}
 }
 
+// stepNames words each build step for a failure message.
+var stepNames = map[string]string{
+	ContainerGate:     "the egress gate",
+	ContainerFetch:    "fetching the build context",
+	ContainerKaniko:   "the image build",
+	ContainerTrivy:    "the vulnerability scan",
+	ContainerSBOM:     "writing the SBOM",
+	ContainerScanGate: "the scan gate",
+	ContainerPush:     "the registry push",
+}
+
+// maxFailureMessage bounds the step message a failed build records.
+const maxFailureMessage = 600
+
+// failureReason is the error a failed build records: the scan verdict when the
+// policy blocked the image, the deadline when the Job ran out of time, or the
+// failed step with the tail of its termination message.
+func (b *Builder) failureReason(out Outcome) string {
+	switch {
+	case out.Scan != nil && out.Scan.Summary.Blocked:
+		return out.Scan.Summary.Reason()
+	case out.DeadlineExceeded:
+		return fmt.Sprintf("the build ran past its %s deadline", b.Config.withDefaults().Deadline)
+	case out.FailedStep == "":
+		return "the build job failed"
+	}
+	name := stepNames[out.FailedStep]
+	if name == "" {
+		name = "the " + out.FailedStep + " step"
+	}
+	msg := fmt.Sprintf("%s failed (exit %d)", name, out.ExitCode)
+	if tail := messageTail(out.Message); tail != "" {
+		msg += ": " + tail
+	}
+	if out.FailedStep == ContainerScanGate && out.ScanErr != nil {
+		msg += "; the scan report could not be read back: " + out.ScanErr.Error()
+	}
+	return msg
+}
+
+// messageTail keeps the last three non-empty lines of a termination message on
+// one line, tabs as spaces and other control characters removed, at most
+// maxFailureMessage bytes.
+func messageTail(m string) string {
+	var lines []string
+	for _, l := range strings.Split(m, "\n") {
+		if l = strings.TrimSpace(Printable(strings.ReplaceAll(strings.TrimRight(l, "\r"), "\t", " "))); l != "" {
+			lines = append(lines, l)
+		}
+	}
+	lines = lines[max(0, len(lines)-3):]
+	out := strings.Join(lines, " | ")
+	if len(out) > maxFailureMessage {
+		out = "…" + strings.ToValidUTF8(out[len(out)-maxFailureMessage:], "")
+	}
+	return out
+}
+
+// Scan returns a build's scan record, or ErrNotFound when the build has none
+// (it failed before the scan, or finished before scans were kept).
+func (b *Builder) Scan(ctx context.Context, id string) (*Scan, error) {
+	return b.Store.GetScan(ctx, id)
+}
+
 // SyncAll reconciles every running build, then starts queued builds oldest
 // first while fewer than MaxConcurrent run. It returns the count advanced to a
 // terminal state. felis-api calls this periodically (spec §16: the scan gate is
@@ -713,9 +842,9 @@ func (b *Builder) finishAt(ctx context.Context, bld *Build, status Status, msg s
 	}
 	if status == StatusFailed {
 		// felis_image_build_failures_total (spec §23) counts builds that reached a
-		// failed terminal state — a kaniko failure or a CRITICAL CVE surfaced by
-		// trivy's --exit-code 1, observed here as the Sync JobFailed/JobUnknown
-		// verdict. Cancellations (StatusCancelled) are deliberately not failures.
+		// failed terminal state — a failed step or a finding the scan policy
+		// blocks on (scan-gate exits 1), observed here as the Sync
+		// JobFailed/JobUnknown verdict. Cancellations (StatusCancelled) are deliberately not failures.
 		// Incremented only after the failed status is persisted, so the counter
 		// never runs ahead of the store. (Submit's job-creation path records its
 		// failure outside finishAt and increments there.)
diff --git a/internal/build/build_test.go b/internal/build/build_test.go
index 5f38832..8612645 100644
--- a/internal/build/build_test.go
+++ b/internal/build/build_test.go
@@ -27,6 +27,7 @@ type fakeStore struct {
 	listOpts  ListOpts
 
 	getManyCalls int
+	scans        map[string]Scan
 }
 
 func newFakeStore() *fakeStore {
@@ -133,6 +134,22 @@ func (f *fakeStore) AddExternalImage(_ context.Context, img Image) error {
 	return nil
 }
 
+func (f *fakeStore) SaveScan(_ context.Context, sc Scan) error {
+	if f.scans == nil {
+		f.scans = map[string]Scan{}
+	}
+	f.scans[sc.BuildID] = sc
+	return nil
+}
+
+func (f *fakeStore) GetScan(_ context.Context, id string) (*Scan, error) {
+	sc, ok := f.scans[id]
+	if !ok {
+		return nil, ErrNotFound
+	}
+	return &sc, nil
+}
+
 func (f *fakeStore) RemoveImage(_ context.Context, ref string) error {
 	if f.removeErr != nil {
 		return f.removeErr
diff --git a/internal/build/jobspec.go b/internal/build/jobspec.go
index 12c2a28..0cb9a66 100644
--- a/internal/build/jobspec.go
+++ b/internal/build/jobspec.go
@@ -27,16 +27,20 @@ const (
 
 // Container names within the build Pod. Kaniko is the initContainer that builds
 // the image into a tarball — its log IS the "build log" an admin watches (spec
-// §16); Trivy is the next initContainer, whose CRITICAL-CVE verdict gates both the
-// push and admission and is surfaced via the build status, not the log stream;
+// §16); Trivy then writes the full vulnerability report, SBOM converts it to
+// CycloneDX, and ScanGate applies the scan policy, whose verdict gates both the
+// push and admission and reaches felis-api through ScanGate's log (scan.go);
 // Push is the main container that publishes the scanned tarball. Exported so the
 // build-log streamer (internal/api.K8sBuildLogStreamer, spec §416 日志流复用 §8)
-// follows the same container this Job defines — one source of truth for the name.
+// and the outcome reader follow the same containers this Job defines — one source
+// of truth for the names.
 const (
-	ContainerGate   = "egress-gate"
-	ContainerKaniko = "kaniko"
-	ContainerTrivy  = "trivy"
-	ContainerPush   = "push"
+	ContainerGate     = "egress-gate"
+	ContainerKaniko   = "kaniko"
+	ContainerTrivy    = "trivy"
+	ContainerSBOM     = "sbom"
+	ContainerScanGate = "scan-gate"
+	ContainerPush     = "push"
 	// ContainerFetch is the initContainer that pulls a submission's build context
 	// from the felis-api internal face and extracts it into the shared emptyDir.
 	// It exists only for an http(s) ContextRef (see BuildJob); a ref Kaniko can
@@ -53,8 +57,20 @@ const (
 	imageVolume    = "image"
 	imageMountPath = "/image"
 	imageTarPath   = imageMountPath + "/image.tar"
+
+	// reportsVolume carries Trivy's JSON report and the CycloneDX SBOM from the
+	// scan steps to scan-gate. Kaniko never mounts it, so the Dockerfile cannot
+	// write a verdict of its own.
+	reportsVolume    = "reports"
+	reportsMountPath = "/reports"
+	trivyReportPath  = reportsMountPath + "/trivy.json"
+	sbomPath         = reportsMountPath + "/sbom.cdx.json"
 )
 
+// reportsSizeLimit bounds the report and SBOM of one image: a modpack's run to a
+// few MiB each.
+var reportsSizeLimit = resource.MustParse("512Mi")
+
 // imageSizeLimit bounds the built image tarball. A modpack image is typically a
 // JRE, a server jar and a few hundred MiB of mods; 10 GiB leaves ample room while
 // still stopping a runaway build from filling the node's disk.
@@ -70,13 +86,19 @@ var contextSizeLimit = resource.MustParse("4Gi")
 // kaniko unpacks the base image into its own root filesystem, which no emptyDir
 // bound covers; it is also the largest limit in the pod, so it becomes the
 // pod-level cap the kubelet holds context + unpacked rootfs + image tarball to.
-// Trivy keeps its vulnerability and Java DBs (about 1.4 GiB live) in its layer.
-// The others write nothing but logs.
+// Trivy keeps its vulnerability and Java DBs in its layer: measured 2026-09-25 at
+// 1374 MiB and 1459 MiB unpacked, and each DB's compressed download sits next to
+// its unpacked copy until the unpack ends, so a 4Gi limit had the kubelet evict
+// the pod mid-download. Its request is the DBs' live size, and the limit leaves
+// room for their growth and the scan's own temporary files. The others write
+// nothing but logs.
 var (
 	gateDisk     = diskBounds{request: resource.MustParse("16Mi"), limit: resource.MustParse("64Mi")}
 	fetchDisk    = diskBounds{request: resource.MustParse("64Mi"), limit: resource.MustParse("256Mi")}
 	kanikoDiskRq = resource.MustParse("1Gi")
-	trivyDisk    = diskBounds{request: resource.MustParse("256Mi"), limit: resource.MustParse("4Gi")}
+	trivyDisk    = diskBounds{request: resource.MustParse("3Gi"), limit: resource.MustParse("8Gi")}
+	sbomDisk     = diskBounds{request: resource.MustParse("16Mi"), limit: resource.MustParse("256Mi")}
+	scanGateDisk = diskBounds{request: resource.MustParse("16Mi"), limit: resource.MustParse("64Mi")}
 	pushDisk     = diskBounds{request: resource.MustParse("16Mi"), limit: resource.MustParse("256Mi")}
 )
 
@@ -123,9 +145,14 @@ type JobParams struct {
 	TrivyJavaDBRepository string
 	KanikoImage           string
 	TrivyImage            string
-	Deadline              time.Duration
-	CPULimit              string
-	MemLimit              string
+	// ScanFailOn, ScanFailUnfixed and ScanAccept are the scan policy scan-gate
+	// applies (ScanPolicy). An empty ScanFailOn applies DefaultScanFailOn.
+	ScanFailOn      []string
+	ScanFailUnfixed bool
+	ScanAccept      []string
+	Deadline        time.Duration
+	CPULimit        string
+	MemLimit        string
 	// DiskLimit caps kaniko's ephemeral storage, and with it the pod's (see
 	// kanikoDiskRq). Empty applies defaultDiskLimit.
 	DiskLimit string
@@ -165,12 +192,16 @@ func buildLabels(p JobParams) map[string]string {
 //   - activeDeadlineSeconds + backoffLimit=0 + per-container CPU, memory and
 //     ephemeral-storage limits so a runaway or poisoned build cannot exhaust the
 //     node (spec §16);
-//   - the Trivy step runs with `--exit-code 1 --severity CRITICAL`, so a
-//     CRITICAL CVE fails the Pod and therefore the Job — the only retained
-//     automatic admission gate (spec §16).
+//   - Trivy writes its full report (no severity filter), trivy convert turns it
+//     into a CycloneDX SBOM, and scan-gate exits 1 when a finding matches the
+//     scan policy (HIGH and CRITICAL with a fixed release, by default), which
+//     fails the Pod and therefore the Job — the only retained automatic
+//     admission gate (spec §16). scan-gate's log carries the report and SBOM to
+//     felis-api, which keeps them on the build.
 //
 // Sequencing: kaniko builds with --no-push into a tarball, trivy scans that
-// tarball, and only then does the push container publish it. So:
+// tarball, scan-gate rules on the report, and only then does the push container
+// publish it. So:
 //
 //   - an image that fails the scan is never published — it used to be pushed to
 //     the final tag first and scanned after, overwriting whatever that tag held;
@@ -178,8 +209,8 @@ func buildLabels(p JobParams) map[string]string {
 //     the untrusted Dockerfile and holds no credential at all, and the registry
 //     refuses anonymous writes (internal/registrygate).
 //
-// The Pod succeeds only if kaniko built, trivy found no CRITICAL CVE, and the push
-// landed.
+// The Pod succeeds only if kaniko built, the scan found nothing the policy blocks,
+// and the push landed.
 func BuildJob(p JobParams) (*batchv1.Job, error) {
 	limits, err := resourceLimits(p.CPULimit, p.MemLimit)
 	if err != nil {
@@ -262,6 +293,9 @@ func BuildJob(p JobParams) (*batchv1.Job, error) {
 			},
 		},
 		SecurityContext: gateSec,
+		// A failed step's last log lines become its termination message, which
+		// Sync records as the build's error (Outcome).
+		TerminationMessagePolicy: corev1.TerminationMessageFallbackToLogsOnError,
 	}
 	initContainers := []corev1.Container{gate}
 	imageMount := corev1.VolumeMount{Name: imageVolume, MountPath: imageMountPath}
@@ -305,9 +339,10 @@ func BuildJob(p JobParams) (*batchv1.Job, error) {
 					Key:                  naming.ServiceTokenSecretKey,
 				}},
 			}},
-			VolumeMounts:    []corev1.VolumeMount{{Name: contextVolume, MountPath: contextMountPath}},
-			Resources:       withDisk(limits, fetchDisk),
-			SecurityContext: fetchSec,
+			VolumeMounts:             []corev1.VolumeMount{{Name: contextVolume, MountPath: contextMountPath}},
+			Resources:                withDisk(limits, fetchDisk),
+			SecurityContext:          fetchSec,
+			TerminationMessagePolicy: corev1.TerminationMessageFallbackToLogsOnError,
 		}
 		initContainers = append(initContainers, fetch)
 		kanikoMounts = append(kanikoMounts, corev1.VolumeMount{Name: contextVolume, MountPath: contextMountPath, ReadOnly: true})
@@ -342,17 +377,21 @@ func BuildJob(p JobParams) (*batchv1.Job, error) {
 			"--insecure-pull",
 			"--skip-tls-verify-pull",
 		},
-		VolumeMounts:    kanikoMounts,
-		Resources:       withDisk(limits, diskBounds{request: kanikoRq, limit: kanikoDisk}),
-		SecurityContext: kanikoSec,
+		VolumeMounts:             kanikoMounts,
+		Resources:                withDisk(limits, diskBounds{request: kanikoRq, limit: kanikoDisk}),
+		SecurityContext:          kanikoSec,
+		TerminationMessagePolicy: corev1.TerminationMessageFallbackToLogsOnError,
 	}
 	initContainers = append(initContainers, kaniko)
 
+	// Trivy reports every severity and every package (--list-all-pkgs is its
+	// default for JSON), so the kept report is complete and doubles as the SBOM's
+	// source; it exits 0 on findings, and scan-gate applies the policy.
 	trivyArgs := []string{
 		"image",
 		"--input", imageTarPath,
-		"--exit-code", "1",
-		"--severity", "CRITICAL",
+		"--format", "json",
+		"--output", trivyReportPath,
 		"--no-progress",
 		"--insecure",
 	}
@@ -367,15 +406,57 @@ func BuildJob(p JobParams) (*batchv1.Job, error) {
 	if p.TrivyJavaDBRepository != "" {
 		trivyArgs = append(trivyArgs, "--java-db-repository", p.TrivyJavaDBRepository)
 	}
+	reportsMount := corev1.VolumeMount{Name: reportsVolume, MountPath: reportsMountPath}
 	trivy := corev1.Container{
-		Name:            ContainerTrivy,
-		Image:           p.TrivyImage,
-		Args:            trivyArgs,
-		VolumeMounts:    []corev1.VolumeMount{{Name: imageVolume, MountPath: imageMountPath, ReadOnly: true}},
-		Resources:       withDisk(limits, trivyDisk),
-		SecurityContext: sec,
+		Name:  ContainerTrivy,
+		Image: p.TrivyImage,
+		Args:  trivyArgs,
+		VolumeMounts: []corev1.VolumeMount{
+			{Name: imageVolume, MountPath: imageMountPath, ReadOnly: true},
+			reportsMount,
+		},
+		Resources:                withDisk(limits, trivyDisk),
+		SecurityContext:          sec,
+		TerminationMessagePolicy: corev1.TerminationMessageFallbackToLogsOnError,
 	}
-	initContainers = append(initContainers, trivy)
+	sbom := corev1.Container{
+		Name:                     ContainerSBOM,
+		Image:                    p.TrivyImage,
+		Args:                     []string{"convert", "--format", "cyclonedx", "--output", sbomPath, trivyReportPath},
+		VolumeMounts:             []corev1.VolumeMount{reportsMount},
+		Resources:                withDisk(limits, sbomDisk),
+		SecurityContext:          sec,
+		TerminationMessagePolicy: corev1.TerminationMessageFallbackToLogsOnError,
+	}
+	failOn := p.ScanFailOn
+	if len(failOn) == 0 {
+		failOn = DefaultScanFailOn
+	}
+	gateArgs := []string{"scan-gate", "--report=" + trivyReportPath, "--sbom=" + sbomPath,
+		"--fail-on=" + strings.Join(failOn, ",")}
+	if p.ScanFailUnfixed {
+		gateArgs = append(gateArgs, "--fail-unfixed")
+	}
+	if len(p.ScanAccept) > 0 {
+		gateArgs = append(gateArgs, "--accept="+strings.Join(p.ScanAccept, ","))
+	}
+	// scan-gate writes its own one-line verdict to the termination log; a log
+	// tail would be the envelope's base64.
+	scanGate := corev1.Container{
+		Name:            ContainerScanGate,
+		Image:           p.FelisImage,
+		Args:            gateArgs,
+		VolumeMounts:    []corev1.VolumeMount{{Name: reportsVolume, MountPath: reportsMountPath, ReadOnly: true}},
+		Resources:       withDisk(limits, scanGateDisk),
+		SecurityContext: gateSec,
+	}
+	initContainers = append(initContainers, trivy, sbom, scanGate)
+	podVolumes = append(podVolumes, corev1.Volume{
+		Name: reportsVolume,
+		VolumeSource: corev1.VolumeSource{EmptyDir: &corev1.EmptyDirVolumeSource{
+			SizeLimit: quantityPtr(reportsSizeLimit),
+		}},
+	})
 
 	// The publish step: the only container that holds the registry credential,
 	// read from a Secret the installer materializes in this namespace. It runs
@@ -401,9 +482,10 @@ func BuildJob(p JobParams) (*batchv1.Job, error) {
 			secretEnv("FELIS_REGISTRY_USERNAME", naming.RegistryPushUsernameKey),
 			secretEnv("FELIS_REGISTRY_PASSWORD", naming.RegistryPushPasswordKey),
 		},
-		VolumeMounts:    []corev1.VolumeMount{{Name: imageVolume, MountPath: imageMountPath, ReadOnly: true}},
-		Resources:       withDisk(limits, pushDisk),
-		SecurityContext: pushSec,
+		VolumeMounts:             []corev1.VolumeMount{{Name: imageVolume, MountPath: imageMountPath, ReadOnly: true}},
+		Resources:                withDisk(limits, pushDisk),
+		SecurityContext:          pushSec,
+		TerminationMessagePolicy: corev1.TerminationMessageFallbackToLogsOnError,
 	}
 
 	job := &batchv1.Job{
diff --git a/internal/build/jobspec_test.go b/internal/build/jobspec_test.go
index 5694b9a..53f7e82 100644
--- a/internal/build/jobspec_test.go
+++ b/internal/build/jobspec_test.go
@@ -1,6 +1,7 @@
 package build
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 	"time"
@@ -161,9 +162,10 @@ func TestBuildJobRequestsAreASchedulableFloor(t *testing.T) {
 }
 
 // kaniko builds the request's exact target into a tarball and never pushes;
-// trivy gates on that tarball with --exit-code 1 --severity CRITICAL; only then
-// does the push container publish it. An image that fails the scan is therefore
-// never in the registry, and the credential is never where the Dockerfile runs.
+// trivy reports on that tarball, trivy convert writes the SBOM, scan-gate rules
+// on the report; only then does the push container publish it. An image that
+// fails the scan is therefore never in the registry, and the credential is never
+// where the Dockerfile runs.
 func TestBuildJobScansBeforePush(t *testing.T) {
 	p := sampleJobParams()
 	job, err := BuildJob(p)
@@ -171,10 +173,10 @@ func TestBuildJobScansBeforePush(t *testing.T) {
 		t.Fatalf("BuildJob: %v", err)
 	}
 	inits := job.Spec.Template.Spec.InitContainers
-	if len(inits) != 3 || inits[0].Name != ContainerGate || inits[1].Name != ContainerKaniko || inits[2].Name != ContainerTrivy {
-		t.Fatalf("initContainers = %v, want [egress-gate kaniko trivy]", initNames(inits))
+	if got := strings.Join(initNames(inits), " "); got != "egress-gate kaniko trivy sbom scan-gate" {
+		t.Fatalf("initContainers = %s, want egress-gate kaniko trivy sbom scan-gate", got)
 	}
-	kaniko, trivy := inits[1], inits[2]
+	kaniko, trivy, sbom, gate := inits[1], inits[2], inits[3], inits[4]
 	for _, want := range []string{"--destination=" + p.ImageRef, "--no-push", "--tar-path=" + imageTarPath} {
 		if !hasArg(kaniko.Args, want) {
 			t.Errorf("kaniko args = %v, want %s", kaniko.Args, want)
@@ -194,19 +196,52 @@ func TestBuildJobScansBeforePush(t *testing.T) {
 		}
 	}
 
-	// The scan gate: a CRITICAL CVE must fail the Pod (and thus the Job) before
-	// the push container ever starts.
+	// The scan: trivy writes the whole report, unfiltered, for scan-gate to rule
+	// on and for the build to keep.
 	if !argPairPresent(trivy.Args, "--input", imageTarPath) {
 		t.Errorf("trivy must scan the built tarball, args=%v", trivy.Args)
 	}
 	if hasArg(trivy.Args, p.ImageRef) {
 		t.Errorf("trivy must not scan the registry ref (nothing is pushed yet), args=%v", trivy.Args)
 	}
-	if !argPairPresent(trivy.Args, "--exit-code", "1") {
-		t.Errorf("trivy must run with --exit-code 1, args=%v", trivy.Args)
+	if !argPairPresent(trivy.Args, "--format", "json") || !argPairPresent(trivy.Args, "--output", "/reports/trivy.json") {
+		t.Errorf("trivy must write its JSON report to /reports/trivy.json, args=%v", trivy.Args)
 	}
-	if !argPairPresent(trivy.Args, "--severity", "CRITICAL") {
-		t.Errorf("trivy must gate on --severity CRITICAL, args=%v", trivy.Args)
+	for _, filter := range []string{"--severity", "--exit-code", "--ignore-unfixed"} {
+		if hasArg(trivy.Args, filter) {
+			t.Errorf("trivy args = %v carry %s: the kept report must be complete, and scan-gate applies the policy", trivy.Args, filter)
+		}
+	}
+	if got := strings.Join(sbom.Args, " "); sbom.Image != p.TrivyImage ||
+		got != "convert --format cyclonedx --output /reports/sbom.cdx.json /reports/trivy.json" {
+		t.Errorf("sbom = %s %q, want the trivy image converting the report to CycloneDX", sbom.Image, got)
+	}
+	// The gate: a finding the policy blocks fails the Pod (and thus the Job)
+	// before the push container ever starts.
+	if got := strings.Join(gate.Args, " "); gate.Image != p.FelisImage ||
+		got != "scan-gate --report=/reports/trivy.json --sbom=/reports/sbom.cdx.json --fail-on=CRITICAL" {
+		t.Errorf("scan-gate = %s %q, want the platform image blocking on CRITICAL by default", gate.Image, got)
+	}
+	mounts := func(c corev1.Container) string {
+		var out []string
+		for _, m := range c.VolumeMounts {
+			out = append(out, fmt.Sprintf("%s:%s:%t", m.Name, m.MountPath, m.ReadOnly))
+		}
+		return strings.Join(out, " ")
+	}
+	for c, want := range map[*corev1.Container]string{
+		&kaniko: "image:/image:false",
+		&trivy:  "image:/image:true reports:/reports:false",
+		&sbom:   "reports:/reports:false",
+		&gate:   "reports:/reports:true",
+	} {
+		if got := mounts(*c); got != want {
+			t.Errorf("%s mounts %q, want %q", c.Name, got, want)
+		}
+	}
+	if gate.SecurityContext == nil || gate.SecurityContext.ReadOnlyRootFilesystem == nil || !*gate.SecurityContext.ReadOnlyRootFilesystem ||
+		gate.SecurityContext.RunAsNonRoot == nil || !*gate.SecurityContext.RunAsNonRoot {
+		t.Errorf("scan-gate must run non-root on a read-only root, got %+v", gate.SecurityContext)
 	}
 	// No DB repositories configured: Trivy keeps its own defaults.
 	if hasArg(trivy.Args, "--db-repository") || hasArg(trivy.Args, "--java-db-repository") {
@@ -254,6 +289,15 @@ func TestBuildJobScansBeforePush(t *testing.T) {
 	if imgVol == nil || imgVol.EmptyDir == nil || imgVol.EmptyDir.SizeLimit == nil {
 		t.Fatalf("image volume must be a size-limited emptyDir, got %#v", imgVol)
 	}
+	var reports *corev1.Volume
+	for i := range job.Spec.Template.Spec.Volumes {
+		if job.Spec.Template.Spec.Volumes[i].Name == "reports" {
+			reports = &job.Spec.Template.Spec.Volumes[i]
+		}
+	}
+	if reports == nil || reports.EmptyDir == nil || reports.EmptyDir.SizeLimit == nil || reports.EmptyDir.SizeLimit.String() != "512Mi" {
+		t.Fatalf("reports volume must be a 512Mi emptyDir, got %#v", reports)
+	}
 	for _, c := range []corev1.Container{trivy, push} {
 		ro := false
 		for _, m := range c.VolumeMounts {
@@ -267,6 +311,45 @@ func TestBuildJobScansBeforePush(t *testing.T) {
 	}
 }
 
+// The scan policy reaches scan-gate verbatim.
+func TestBuildJobScanPolicyReachesScanGate(t *testing.T) {
+	p := sampleJobParams()
+	p.ScanFailOn = []string{"CRITICAL", "HIGH", "MEDIUM"}
+	p.ScanFailUnfixed = true
+	p.ScanAccept = []string{"CVE-2021-35515", "aws-access-key-id"}
+	job, err := BuildJob(p)
+	if err != nil {
+		t.Fatalf("BuildJob: %v", err)
+	}
+	gate := job.Spec.Template.Spec.InitContainers[4]
+	if got := strings.Join(gate.Args, " "); got != "scan-gate --report=/reports/trivy.json --sbom=/reports/sbom.cdx.json --fail-on=CRITICAL,HIGH,MEDIUM --fail-unfixed --accept=CVE-2021-35515,aws-access-key-id" {
+		t.Errorf("scan-gate args = %q", got)
+	}
+}
+
+// A failed step's last log lines become its termination message, which Sync
+// records as the build's error. scan-gate writes its own verdict there instead:
+// its log tail is the envelope's base64.
+func TestBuildJobStepsLeaveTheirLastLogLines(t *testing.T) {
+	p := sampleJobParams()
+	p.ContextRef = "http://felis-api-internal.felis.svc:8081/internal/v1/submissions/sub-1/context"
+	job, err := BuildJob(p)
+	if err != nil {
+		t.Fatalf("BuildJob: %v", err)
+	}
+	all := append([]corev1.Container{}, job.Spec.Template.Spec.InitContainers...)
+	all = append(all, job.Spec.Template.Spec.Containers...)
+	var got []string
+	for _, c := range all {
+		got = append(got, fmt.Sprintf("%s=%s", c.Name, c.TerminationMessagePolicy))
+	}
+	want := "egress-gate=FallbackToLogsOnError context-fetch=FallbackToLogsOnError kaniko=FallbackToLogsOnError " +
+		"trivy=FallbackToLogsOnError sbom=FallbackToLogsOnError scan-gate= push=FallbackToLogsOnError"
+	if strings.Join(got, " ") != want {
+		t.Errorf("termination message policies = %s\nwant %s", strings.Join(got, " "), want)
+	}
+}
+
 func TestBuildJobNeedsFelisImage(t *testing.T) {
 	p := sampleJobParams()
 	p.FelisImage = ""
@@ -423,9 +506,8 @@ func TestBuildJobFetchesHTTPContext(t *testing.T) {
 		t.Fatalf("BuildJob: %v", err)
 	}
 	inits := job.Spec.Template.Spec.InitContainers
-	if len(inits) != 4 || inits[0].Name != ContainerGate || inits[1].Name != ContainerFetch ||
-		inits[2].Name != ContainerKaniko || inits[3].Name != ContainerTrivy {
-		t.Fatalf("initContainers = %v, want [%s %s %s %s]", initNames(inits), ContainerGate, ContainerFetch, ContainerKaniko, ContainerTrivy)
+	if got := strings.Join(initNames(inits), " "); got != "egress-gate context-fetch kaniko trivy sbom scan-gate" {
+		t.Fatalf("initContainers = %s, want egress-gate context-fetch kaniko trivy sbom scan-gate", got)
 	}
 	fetch, kaniko := inits[1], inits[2]
 	if fetch.Image != p.FelisImage {
@@ -500,8 +582,8 @@ func TestBuildJobNativeContextNeedsNoFetch(t *testing.T) {
 	if err != nil {
 		t.Fatalf("BuildJob: %v", err)
 	}
-	if inits := job.Spec.Template.Spec.InitContainers; len(inits) != 3 || inits[1].Name != ContainerKaniko {
-		t.Errorf("a native ref must render just the gate, kaniko and trivy, got %v", initNames(inits))
+	if got := strings.Join(initNames(job.Spec.Template.Spec.InitContainers), " "); got != "egress-gate kaniko trivy sbom scan-gate" {
+		t.Errorf("a native ref must render no fetch step, got %s", got)
 	}
 	for _, v := range job.Spec.Template.Spec.Volumes {
 		if v.Name == contextVolume {
@@ -611,6 +693,15 @@ func TestBuildJobBoundsEphemeralStorage(t *testing.T) {
 		if c.Name == ContainerKaniko && lim.String() != defaultDiskLimit {
 			t.Errorf("kaniko ephemeral-storage limit = %s, want the default %s", lim.String(), defaultDiskLimit)
 		}
+		// Trivy holds its two DBs (2.8 GiB unpacked in 2026) plus a download and
+		// the scan's temporary files; the SBOM step writes one file; scan-gate's
+		// own log, the envelope of up to 9 MiB, counts against its cap.
+		if want, ok := map[string]string{"trivy": "8Gi", "sbom": "256Mi", "scan-gate": "64Mi"}[c.Name]; ok && lim.String() != want {
+			t.Errorf("%s ephemeral-storage limit = %s, want %s", c.Name, lim.String(), want)
+		}
+		if c.Name == ContainerTrivy && req.String() != "3Gi" {
+			t.Errorf("trivy ephemeral-storage request = %s, want 3Gi, the DBs' live size", req.String())
+		}
 	}
 	p.DiskLimit = "512Mi"
 	if job, err = BuildJob(p); err != nil {
diff --git a/internal/build/k8sjobs.go b/internal/build/k8sjobs.go
index f88f792..bfeaef9 100644
--- a/internal/build/k8sjobs.go
+++ b/internal/build/k8sjobs.go
@@ -66,8 +66,9 @@ func (k *K8sJobs) JobPhase(ctx context.Context, jobName string) (JobPhase, error
 		case batchv1.JobComplete:
 			return JobSucceeded, nil
 		case batchv1.JobFailed:
-			// Covers a CRITICAL CVE (trivy --exit-code 1), a kaniko or push
-			// failure, and DeadlineExceeded — all are a rejected build.
+			// Covers a scan the policy blocked (scan-gate exits 1), a failed
+			// build, scan or push step, and DeadlineExceeded — all are a
+			// rejected build.
 			return JobFailed, nil
 		}
 	}
diff --git a/internal/build/k8soutcomes.go b/internal/build/k8soutcomes.go
new file mode 100644
index 0000000..b1fa046
--- /dev/null
+++ b/internal/build/k8soutcomes.go
@@ -0,0 +1,104 @@
+package build
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	batchv1 "k8s.io/api/batch/v1"
+	corev1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+)
+
+// maxScanLogBytes bounds the scan-gate log Outcome reads: the envelope (at most
+// MaxEnvelopeBytes of gzip, a third larger in base64) plus the verdict lines.
+const maxScanLogBytes = MaxEnvelopeBytes/3*4 + 1<<20
+
+// K8sOutcomes is the production JobOutcomes. It reads the build pod's container
+// statuses and scan-gate's log through the typed client, uncached: felis-api
+// holds pods list and pods/log get in the build namespace for the log stream
+// already, and a controller-runtime read would start a cluster-wide pod
+// informer.
+type K8sOutcomes struct {
+	cs        kubernetes.Interface
+	namespace string
+}
+
+// NewK8sOutcomes reads build pods in cfg's namespace.
+func NewK8sOutcomes(cs kubernetes.Interface, cfg Config) *K8sOutcomes {
+	return &K8sOutcomes{cs: cs, namespace: cfg.withDefaults().Namespace}
+}
+
+// Outcome reports what the finished build pod of buildID left: the Job's
+// deadline verdict, the first container that exited non-zero, and scan-gate's
+// envelope. A pod already gone yields what the Job still says. Only API reads
+// that may succeed on a retry return an error; an unreadable scan log becomes
+// Outcome.ScanErr, so a build never stays unfinished over it.
+func (k *K8sOutcomes) Outcome(ctx context.Context, buildID string) (Outcome, error) {
+	var out Outcome
+	job, err := k.cs.BatchV1().Jobs(k.namespace).Get(ctx, BuildJobName(buildID), metav1.GetOptions{})
+	switch {
+	case apierrors.IsNotFound(err):
+	case err != nil:
+		return out, err
+	default:
+		out.DeadlineExceeded = jobDeadlineExceeded(job)
+	}
+	pods, err := k.cs.CoreV1().Pods(k.namespace).List(ctx, metav1.ListOptions{LabelSelector: LabelBuildID + "=" + buildID})
+	if err != nil {
+		return out, err
+	}
+	if len(pods.Items) == 0 {
+		return out, nil
+	}
+	// backoffLimit 0 and restartPolicy Never: the Job makes at most one pod.
+	pod := &pods.Items[0]
+	gateRan := false
+	for _, st := range append(append([]corev1.ContainerStatus{}, pod.Status.InitContainerStatuses...), pod.Status.ContainerStatuses...) {
+		t := st.State.Terminated
+		if t == nil {
+			continue
+		}
+		if st.Name == ContainerScanGate {
+			gateRan = true
+		}
+		if t.ExitCode != 0 && out.FailedStep == "" {
+			out.FailedStep, out.ExitCode, out.Message = st.Name, t.ExitCode, t.Message
+		}
+	}
+	if !gateRan {
+		return out, nil
+	}
+	limit := int64(maxScanLogBytes)
+	stream, err := k.cs.CoreV1().Pods(k.namespace).GetLogs(pod.Name, &corev1.PodLogOptions{
+		Container: ContainerScanGate, LimitBytes: &limit,
+	}).Stream(ctx)
+	if err != nil {
+		out.ScanErr = fmt.Errorf("open the scan-gate log: %w", err)
+		return out, nil
+	}
+	defer stream.Close()
+	env, err := ReadScanEnvelope(stream)
+	switch {
+	case errors.Is(err, ErrNoScanEnvelope):
+		out.ScanErr = errors.New("the scan-gate log holds no scan envelope")
+	case err != nil:
+		out.ScanErr = err
+	default:
+		out.Scan = env
+	}
+	return out, nil
+}
+
+// jobDeadlineExceeded reports a Job the controller failed for running past
+// activeDeadlineSeconds; it deletes the pod, so the Job is all that says so.
+func jobDeadlineExceeded(job *batchv1.Job) bool {
+	for _, c := range job.Status.Conditions {
+		if c.Type == batchv1.JobFailed && c.Status == corev1.ConditionTrue && c.Reason == batchv1.JobReasonDeadlineExceeded {
+			return true
+		}
+	}
+	return false
+}
diff --git a/internal/build/outcome_test.go b/internal/build/outcome_test.go
new file mode 100644
index 0000000..962ab60
--- /dev/null
+++ b/internal/build/outcome_test.go
@@ -0,0 +1,293 @@
+package build
+
+import (
+	"bytes"
+	"compress/gzip"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"testing"
+
+	batchv1 "k8s.io/api/batch/v1"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes/fake"
+	k8stesting "k8s.io/client-go/testing"
+)
+
+type fakeOutcomes struct {
+	out   Outcome
+	err   error
+	calls []string
+}
+
+func (f *fakeOutcomes) Outcome(_ context.Context, id string) (Outcome, error) {
+	f.calls = append(f.calls, id)
+	return f.out, f.err
+}
+
+// runningBuild wires a Builder whose bld-1 is building under a Job in phase.
+func runningBuild(t *testing.T, phase JobPhase, out *fakeOutcomes) (*Builder, *fakeStore) {
+	t.Helper()
+	b, st, jb := newBuilder()
+	if out != nil {
+		b.Outcomes = out
+	}
+	st.builds["bld-1"] = &Build{ID: "bld-1", ImageRef: "registry.felis.svc:5000/mc/pack:1", Status: StatusBuilding,
+		JobName: "build-bld-1", RequestedBy: "admin@example.net", CreatedAt: testNow}
+	jb.phase = phase
+	return b, st
+}
+
+func blockedEnvelope(t *testing.T) *ScanEnvelope {
+	t.Helper()
+	s, err := Summarize([]byte(trivyFixture), ScanPolicy{FailOn: []string{"CRITICAL", "HIGH"}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	return &ScanEnvelope{Summary: s, Report: json.RawMessage(trivyFixture), SBOM: json.RawMessage(`{"bomFormat":"CycloneDX"}`)}
+}
+
+func gunzipString(t *testing.T, b []byte) string {
+	t.Helper()
+	zr, err := gzip.NewReader(bytes.NewReader(b))
+	if err != nil {
+		t.Fatal(err)
+	}
+	raw, err := io.ReadAll(zr)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(raw)
+}
+
+// A build the scan blocked records the blocking findings as its error and keeps
+// the report and SBOM.
+func TestSyncRecordsTheScanThatBlocked(t *testing.T) {
+	out := &fakeOutcomes{out: Outcome{FailedStep: ContainerScanGate, ExitCode: 1, Message: "the scan blocked…", Scan: blockedEnvelope(t)}}
+	b, st := runningBuild(t, JobFailed, out)
+	bld, err := b.Sync(context.Background(), "bld-1")
+	if err != nil {
+		t.Fatalf("Sync: %v", err)
+	}
+	if bld.Status != StatusFailed || bld.Error != "the scan blocked the image: 2 CRITICAL, 1 HIGH (CVE-2024-0001, aws-access-key-id, CVE-2024-0004)" {
+		t.Errorf("build = %s %q", bld.Status, bld.Error)
+	}
+	if st.builds["bld-1"].Error != bld.Error {
+		t.Errorf("stored error = %q", st.builds["bld-1"].Error)
+	}
+	sc, ok := st.scans["bld-1"]
+	if !ok {
+		t.Fatal("no scan stored")
+	}
+	if !sc.Summary.Blocked || !sc.ScannedAt.Equal(testNow) || gunzipString(t, sc.SBOMGz) != `{"bomFormat":"CycloneDX"}` ||
+		!strings.Contains(gunzipString(t, sc.ReportGz), `"CVE-2024-0001"`) {
+		t.Errorf("scan = blocked %t at %s, sbom %q", sc.Summary.Blocked, sc.ScannedAt, gunzipString(t, sc.SBOMGz))
+	}
+	if len(st.admitted) != 0 {
+		t.Errorf("a blocked image was admitted: %v", st.admitted)
+	}
+	if !reflect.DeepEqual(out.calls, []string{"bld-1"}) {
+		t.Errorf("outcome reads = %v", out.calls)
+	}
+}
+
+// An admitted image keeps its scan too.
+func TestSyncKeepsTheScanOfAnAdmittedImage(t *testing.T) {
+	env := blockedEnvelope(t)
+	env.Summary.Blocked = false
+	b, st := runningBuild(t, JobSucceeded, &fakeOutcomes{out: Outcome{Scan: env}})
+	bld, err := b.Sync(context.Background(), "bld-1")
+	if err != nil {
+		t.Fatalf("Sync: %v", err)
+	}
+	if bld.Status != StatusSucceeded || len(st.admitted) != 1 {
+		t.Fatalf("build %s, admitted %v", bld.Status, st.admitted)
+	}
+	if sc, ok := st.scans["bld-1"]; !ok || sc.Summary.Blocked || sc.Summary.Packages != 5 {
+		t.Errorf("scan = %+v, %t", sc.Summary, ok)
+	}
+}
+
+func TestSyncNamesWhatEndedAFailedBuild(t *testing.T) {
+	long := strings.Repeat("x", 700)
+	for _, tc := range []struct {
+		name string
+		out  Outcome
+		want string
+	}{
+		{"kaniko", Outcome{FailedStep: ContainerKaniko, ExitCode: 1,
+			Message: "INFO[0003] RUN ./setup.sh\nstep 1\n\nstep 2\r\nerror building image: error building stage: failed to execute command: exit status 2\n"},
+			"the image build failed (exit 1): step 1 | step 2 | error building image: error building stage: failed to execute command: exit status 2"},
+		{"trivy", Outcome{FailedStep: ContainerTrivy, ExitCode: 1, Message: "FATAL\tFatal error\tinit error: DB error: failed to download vulnerability DB"},
+			"the vulnerability scan failed (exit 1): FATAL Fatal error init error: DB error: failed to download vulnerability DB"},
+		{"push", Outcome{FailedStep: ContainerPush, ExitCode: 1}, "the registry push failed (exit 1)"},
+		{"unknown step", Outcome{FailedStep: "sidecar", ExitCode: 137}, "the sidecar step failed (exit 137)"},
+		{"unreadable scan", Outcome{FailedStep: ContainerScanGate, ExitCode: 2, Message: "the scan report is unreadable: EOF",
+			ScanErr: errors.New("the scan-gate log holds no scan envelope")},
+			"the scan gate failed (exit 2): the scan report is unreadable: EOF; the scan report could not be read back: the scan-gate log holds no scan envelope"},
+		{"deadline", Outcome{DeadlineExceeded: true}, "the build ran past its 30m0s deadline"},
+		{"nothing known", Outcome{}, "the build job failed"},
+		{"long message", Outcome{FailedStep: ContainerKaniko, ExitCode: 1, Message: "start " + long},
+			"the image build failed (exit 1): …" + strings.Repeat("x", 600)},
+	} {
+		b, _ := runningBuild(t, JobFailed, &fakeOutcomes{out: tc.out})
+		bld, err := b.Sync(context.Background(), "bld-1")
+		if err != nil {
+			t.Fatalf("%s: Sync: %v", tc.name, err)
+		}
+		if bld.Error != tc.want {
+			t.Errorf("%s: error = %q\nwant %q", tc.name, bld.Error, tc.want)
+		}
+	}
+}
+
+// A vanished Job has no pod to read; a failed read leaves the build to the next
+// tick; without an outcome reader Sync records a plain failure.
+func TestSyncOutcomeEdges(t *testing.T) {
+	out := &fakeOutcomes{}
+	b, _ := runningBuild(t, JobUnknown, out)
+	bld, err := b.Sync(context.Background(), "bld-1")
+	if err != nil || bld.Error != "the build job is gone: it was deleted before it finished" || len(out.calls) != 0 {
+		t.Errorf("gone job: %q, %v, reads %v", bld.Error, err, out.calls)
+	}
+
+	b, st := runningBuild(t, JobFailed, &fakeOutcomes{err: errors.New("apiserver unavailable")})
+	if _, err := b.Sync(context.Background(), "bld-1"); err == nil || err.Error() != "apiserver unavailable" {
+		t.Errorf("read failure: err = %v", err)
+	}
+	if st.builds["bld-1"].Status != StatusBuilding {
+		t.Errorf("a failed outcome read finished the build: %s", st.builds["bld-1"].Status)
+	}
+
+	b, _ = runningBuild(t, JobFailed, nil)
+	if bld, err := b.Sync(context.Background(), "bld-1"); err != nil || bld.Error != "the build job failed" {
+		t.Errorf("no reader: %q, %v", bld.Error, err)
+	}
+
+	out = &fakeOutcomes{}
+	b, _ = runningBuild(t, JobRunning, out)
+	if bld, err := b.Sync(context.Background(), "bld-1"); err != nil || bld.Status != StatusBuilding || len(out.calls) != 0 {
+		t.Errorf("running: %s, %v, reads %v", bld.Status, err, out.calls)
+	}
+}
+
+func TestSubmitCarriesTheScanPolicy(t *testing.T) {
+	b, _, jb := newBuilder()
+	if _, err := b.Submit(context.Background(), goodRequest()); err != nil {
+		t.Fatal(err)
+	}
+	b.Config.ScanFailOn = []string{"CRITICAL", "HIGH"}
+	b.Config.ScanFailUnfixed = true
+	b.Config.ScanAccept = []string{"CVE-2021-35515"}
+	req := goodRequest()
+	req.ImageRef = "registry.felis.svc:5000/mc-paper:2.0"
+	if _, err := b.Submit(context.Background(), req); err != nil {
+		t.Fatal(err)
+	}
+	if len(jb.created) != 2 {
+		t.Fatalf("jobs = %d", len(jb.created))
+	}
+	if got := jb.created[0]; !reflect.DeepEqual(got.ScanFailOn, []string{"CRITICAL"}) || got.ScanFailUnfixed || got.ScanAccept != nil {
+		t.Errorf("default policy = %v unfixed=%t accept=%v", got.ScanFailOn, got.ScanFailUnfixed, got.ScanAccept)
+	}
+	if got := jb.created[1]; !reflect.DeepEqual(got.ScanFailOn, []string{"CRITICAL", "HIGH"}) || !got.ScanFailUnfixed ||
+		!reflect.DeepEqual(got.ScanAccept, []string{"CVE-2021-35515"}) {
+		t.Errorf("configured policy = %v unfixed=%t accept=%v", got.ScanFailOn, got.ScanFailUnfixed, got.ScanAccept)
+	}
+}
+
+func TestBuilderScanReadsTheStore(t *testing.T) {
+	b, st, _ := newBuilder()
+	if _, err := b.Scan(context.Background(), "bld-9"); !errors.Is(err, ErrNotFound) {
+		t.Errorf("missing scan: err = %v", err)
+	}
+	st.scans = map[string]Scan{"bld-9": {BuildID: "bld-9", Summary: ScanSummary{Packages: 42}}}
+	if sc, err := b.Scan(context.Background(), "bld-9"); err != nil || sc.Summary.Packages != 42 {
+		t.Errorf("scan = %+v, %v", sc, err)
+	}
+}
+
+// K8sOutcomes reads the first failed container in pod order, the Job's deadline
+// verdict, and looks for an envelope only when scan-gate ran. The fake clientset
+// answers every log read with "fake logs", which holds no envelope.
+func TestK8sOutcomesReadsThePod(t *testing.T) {
+	ctx := context.Background()
+	term := func(name string, code int32, msg string) corev1.ContainerStatus {
+		return corev1.ContainerStatus{Name: name, State: corev1.ContainerState{Terminated: &corev1.ContainerStateTerminated{ExitCode: code, Message: msg}}}
+	}
+	pod := func(inits ...corev1.ContainerStatus) *corev1.Pod {
+		return &corev1.Pod{
+			ObjectMeta: metav1.ObjectMeta{Name: "build-bld-1-abcde", Namespace: "felis-build", Labels: map[string]string{LabelBuildID: "bld-1"}},
+			Status:     corev1.PodStatus{InitContainerStatuses: inits},
+		}
+	}
+	job := &batchv1.Job{ObjectMeta: metav1.ObjectMeta{Name: "build-bld-1", Namespace: "felis-build"}}
+
+	// Another build's pod, failed at a different step, sorts ahead of bld-1's.
+	other := pod(term("egress-gate", 7, "denied"))
+	other.Name, other.Labels = "build-bld-0-zzzzz", map[string]string{LabelBuildID: "bld-0"}
+	k := NewK8sOutcomes(fake.NewSimpleClientset(job, other, pod(term("egress-gate", 0, ""), term("kaniko", 1, "boom"),
+		corev1.ContainerStatus{Name: "trivy", State: corev1.ContainerState{Waiting: &corev1.ContainerStateWaiting{}}})), Config{})
+	out, err := k.Outcome(ctx, "bld-1")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if out.FailedStep != "kaniko" || out.ExitCode != 1 || out.Message != "boom" || out.Scan != nil || out.ScanErr != nil || out.DeadlineExceeded {
+		t.Errorf("kaniko failure = %+v", out)
+	}
+
+	cs := fake.NewSimpleClientset(job, pod(term("egress-gate", 0, ""), term("kaniko", 0, ""),
+		term("trivy", 0, ""), term("sbom", 0, ""), term("scan-gate", 1, "the scan blocked the image: 1 HIGH (CVE-1)")))
+	k = NewK8sOutcomes(cs, Config{})
+	out, err = k.Outcome(ctx, "bld-1")
+	if err != nil {
+		t.Fatal(err)
+	}
+	// The fake API serves "fake logs" for every log read, which holds no envelope.
+	if out.FailedStep != "scan-gate" || out.ScanErr == nil || out.ScanErr.Error() != "the scan-gate log holds no scan envelope" {
+		t.Errorf("scan-gate failure = %+v", out)
+	}
+	var logReads []string
+	for _, a := range cs.Actions() {
+		if a.GetSubresource() == "log" {
+			o := a.(k8stesting.GenericAction).GetValue().(*corev1.PodLogOptions)
+			logReads = append(logReads, fmt.Sprintf("%s/%s limit %d", a.GetNamespace(), o.Container, *o.LimitBytes))
+		}
+	}
+	if !reflect.DeepEqual(logReads, []string{"felis-build/scan-gate limit 9437184"}) {
+		t.Errorf("log reads = %q", logReads)
+	}
+
+	pushed := pod(term("egress-gate", 0, ""), term("kaniko", 0, ""), term("trivy", 0, ""), term("sbom", 0, ""), term("scan-gate", 0, "the scan passed"))
+	pushed.Status.ContainerStatuses = []corev1.ContainerStatus{term("push", 1, "UNAUTHORIZED: authentication required")}
+	k = NewK8sOutcomes(fake.NewSimpleClientset(job, pushed), Config{})
+	out, err = k.Outcome(ctx, "bld-1")
+	if err != nil || out.FailedStep != "push" || out.ExitCode != 1 || out.Message != "UNAUTHORIZED: authentication required" {
+		t.Errorf("push failure = %+v, %v", out, err)
+	}
+
+	deadline := job.DeepCopy()
+	deadline.Status.Conditions = []batchv1.JobCondition{{Type: batchv1.JobFailed, Status: corev1.ConditionTrue, Reason: "DeadlineExceeded"}}
+	k = NewK8sOutcomes(fake.NewSimpleClientset(deadline), Config{})
+	out, err = k.Outcome(ctx, "bld-1")
+	if err != nil || !out.DeadlineExceeded || out.FailedStep != "" {
+		t.Errorf("deadline = %+v, %v", out, err)
+	}
+
+	backoff := job.DeepCopy()
+	backoff.Status.Conditions = []batchv1.JobCondition{{Type: batchv1.JobFailed, Status: corev1.ConditionTrue, Reason: "BackoffLimitExceeded"}}
+	k = NewK8sOutcomes(fake.NewSimpleClientset(backoff), Config{})
+	if out, err = k.Outcome(ctx, "bld-1"); err != nil || out.DeadlineExceeded {
+		t.Errorf("backoff = %+v, %v", out, err)
+	}
+
+	k = NewK8sOutcomes(fake.NewSimpleClientset(pod(term("egress-gate", 0, ""))), Config{Namespace: "elsewhere"})
+	if out, err = k.Outcome(ctx, "bld-1"); err != nil || out.FailedStep != "" {
+		t.Errorf("other namespace = %+v, %v", out, err)
+	}
+}
diff --git a/internal/build/pgstore.go b/internal/build/pgstore.go
index 199996a..d5d8f28 100644
--- a/internal/build/pgstore.go
+++ b/internal/build/pgstore.go
@@ -3,11 +3,13 @@ package build
 import (
 	"context"
 	"database/sql"
+	"encoding/json"
 	"time"
 )
 
 // PGStore is the production Store backed by Postgres (spec §6, §16). It writes
-// the two tables of the build subsystem — image_builds and image_whitelist —
+// the tables of the build subsystem — image_builds, image_build_scans and
+// image_whitelist —
 // and is the *only* component that holds database credentials: the build Pod
 // never does (the weak-SA red line). The SQL here is exercised by integration
 // tests against a live database, not the hermetic build_test.go suite. Every
@@ -247,3 +249,40 @@ func (s *PGStore) RemoveImage(ctx context.Context, imageRef string) error {
 	}
 	return nil
 }
+
+// SaveScan upserts the scan record of a build. A re-read of the same pod writes
+// the same record, so Sync may retry freely.
+func (s *PGStore) SaveScan(ctx context.Context, sc Scan) error {
+	summary, err := json.Marshal(sc.Summary)
+	if err != nil {
+		return err
+	}
+	const q = `INSERT INTO image_build_scans
+		(build_id, blocked, summary, report_gz, sbom_gz, scanned_at)
+		VALUES ($1, $2, $3, $4, $5, $6)
+		ON CONFLICT (build_id) DO UPDATE
+		SET blocked = EXCLUDED.blocked, summary = EXCLUDED.summary,
+			report_gz = EXCLUDED.report_gz, sbom_gz = EXCLUDED.sbom_gz,
+			scanned_at = EXCLUDED.scanned_at`
+	_, err = s.db.ExecContext(ctx, q, sc.BuildID, sc.Summary.Blocked, summary, sc.ReportGz, sc.SBOMGz, sc.ScannedAt)
+	return err
+}
+
+func (s *PGStore) GetScan(ctx context.Context, buildID string) (*Scan, error) {
+	const q = `SELECT build_id, summary, report_gz, sbom_gz, scanned_at
+		FROM image_build_scans WHERE build_id = $1`
+	var (
+		sc      Scan
+		summary []byte
+	)
+	switch err := s.db.QueryRowContext(ctx, q, buildID).Scan(&sc.BuildID, &summary, &sc.ReportGz, &sc.SBOMGz, &sc.ScannedAt); {
+	case err == sql.ErrNoRows:
+		return nil, ErrNotFound
+	case err != nil:
+		return nil, err
+	}
+	if err := json.Unmarshal(summary, &sc.Summary); err != nil {
+		return nil, err
+	}
+	return &sc, nil
+}
diff --git a/internal/build/scan.go b/internal/build/scan.go
new file mode 100644
index 0000000..d82f6ff
--- /dev/null
+++ b/internal/build/scan.go
@@ -0,0 +1,452 @@
+package build
+
+import (
+	"bufio"
+	"bytes"
+	"compress/gzip"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"regexp"
+	"slices"
+	"sort"
+	"strings"
+	"time"
+)
+
+// The scan gate. Trivy scans the built tarball with no severity filter and writes
+// its full JSON report (every package, every finding); `trivy convert` turns that
+// report into a CycloneDX SBOM; then `felis scan-gate` applies the ScanPolicy,
+// prints a readable verdict, and appends the verdict, the report and the SBOM to
+// its own log inside a framed, checksummed envelope. felis-api already reads
+// build pod logs, so when the Job finishes Sync reads that envelope back and keeps
+// all three on the build: a blocked build says which findings blocked it, and an
+// admitted image has its report and SBOM on record.
+
+// Severities are the levels Trivy assigns, most severe first.
+var Severities = []string{"CRITICAL", "HIGH", "MEDIUM", "LOW", "UNKNOWN"}
+
+// DefaultScanFailOn is the severities that block an image when felis.toml names
+// none. HIGH is left to the operator: the platform's own felis/paper image
+// carries fixable HIGH findings inside upstream paper.jar (its bundled
+// commons-compress and plexus-utils), so blocking on HIGH out of the box fails
+// every build FROM it until those ids are listed in scan_accept.
+var DefaultScanFailOn = []string{"CRITICAL"}
+
+// ScanPolicy decides which findings block an image.
+type ScanPolicy struct {
+	// FailOn lists the severities that block, most severe first.
+	FailOn []string `json:"fail_on"`
+	// FailUnfixed makes a vulnerability with no fixed release block too. Off by
+	// default: a submitter cannot upgrade past it, and the report still lists it.
+	// A leaked secret always counts as fixable.
+	FailUnfixed bool `json:"fail_unfixed"`
+	// Accept lists the vulnerability ids and secret rule ids an administrator
+	// accepted as known risks: a finding under one of them is still counted and
+	// listed, marked accepted, and never blocks.
+	Accept []string `json:"accept,omitempty"`
+}
+
+// scanIDPattern is the shape of a finding id: CVE-2024-3094, GHSA-…, DLA-…,
+// aws-access-key-id. It keeps commas and spaces out of the scan-gate flag.
+var scanIDPattern = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9._:-]{0,127}$`)
+
+// ParseScanAccept reads a comma-separated list of accepted finding ids, in the
+// order given, without repeats. An empty list is valid.
+func ParseScanAccept(s string) ([]string, error) {
+	var out []string
+	for _, id := range strings.Split(s, ",") {
+		id = strings.TrimSpace(id)
+		if id == "" {
+			continue
+		}
+		if !scanIDPattern.MatchString(id) {
+			return nil, fmt.Errorf("%q is not a vulnerability id or secret rule id", id)
+		}
+		if !slices.Contains(out, id) {
+			out = append(out, id)
+		}
+	}
+	return out, nil
+}
+
+// ParseSeverities reads a comma-separated severity list ("HIGH,CRITICAL"),
+// case-insensitively, into Severities order without repeats.
+func ParseSeverities(s string) ([]string, error) {
+	seen := map[string]bool{}
+	for _, part := range strings.Split(s, ",") {
+		part = strings.ToUpper(strings.TrimSpace(part))
+		if part == "" {
+			continue
+		}
+		if !slices.Contains(Severities, part) {
+			return nil, fmt.Errorf("unknown severity %q (use %s)", part, strings.Join(Severities, ", "))
+		}
+		seen[part] = true
+	}
+	var out []string
+	for _, sev := range Severities {
+		if seen[sev] {
+			out = append(out, sev)
+		}
+	}
+	if len(out) == 0 {
+		return nil, errors.New("no severity named")
+	}
+	return out, nil
+}
+
+// ScanFinding is one vulnerability or leaked secret in a scan report.
+type ScanFinding struct {
+	ID        string `json:"id"`
+	Kind      string `json:"kind"` // "vulnerability" or "secret"
+	Severity  string `json:"severity"`
+	Package   string `json:"package,omitempty"`
+	Installed string `json:"installed,omitempty"`
+	Fixed     string `json:"fixed,omitempty"`
+	Target    string `json:"target"`
+	Title     string `json:"title,omitempty"`
+	Blocking  bool   `json:"blocking"`
+	// Accepted marks a finding whose id the policy accepts; it never blocks.
+	Accepted bool `json:"accepted,omitempty"`
+}
+
+// Finding kinds.
+const (
+	FindingVulnerability = "vulnerability"
+	FindingSecret        = "secret"
+)
+
+// MaxSummaryFindings caps the findings a summary lists. Counts and
+// BlockingCounts still cover every finding, and the stored report has them all.
+const MaxSummaryFindings = 100
+
+// ScanSummary is the verdict scan-gate reaches on one report.
+type ScanSummary struct {
+	Policy   ScanPolicy `json:"policy"`
+	Blocked  bool       `json:"blocked"`
+	Packages int        `json:"packages"`
+	// Counts holds every finding by severity; BlockingCounts the ones the policy
+	// blocks on.
+	Counts         map[string]int `json:"counts"`
+	BlockingCounts map[string]int `json:"blocking_counts"`
+	// Findings lists blocking findings first, then the rest, most severe first,
+	// at most MaxSummaryFindings of them.
+	Findings []ScanFinding `json:"findings"`
+	// Omitted names the documents ("sbom", "report") left out of the envelope to
+	// keep it inside a pod log.
+	Omitted []string `json:"omitted,omitempty"`
+}
+
+// trivyReport is the part of Trivy's JSON report (SchemaVersion 2) the gate reads.
+type trivyReport struct {
+	SchemaVersion int `json:"SchemaVersion"`
+	Results       []struct {
+		Target          string     `json:"Target"`
+		Packages        []struct{} `json:"Packages"`
+		Vulnerabilities []struct {
+			VulnerabilityID  string `json:"VulnerabilityID"`
+			PkgName          string `json:"PkgName"`
+			InstalledVersion string `json:"InstalledVersion"`
+			FixedVersion     string `json:"FixedVersion"`
+			Status           string `json:"Status"`
+			Severity         string `json:"Severity"`
+			Title            string `json:"Title"`
+		} `json:"Vulnerabilities"`
+		Secrets []struct {
+			RuleID   string `json:"RuleID"`
+			Severity string `json:"Severity"`
+			Title    string `json:"Title"`
+		} `json:"Secrets"`
+	} `json:"Results"`
+}
+
+// Summarize applies policy to a Trivy JSON report.
+func Summarize(report []byte, policy ScanPolicy) (ScanSummary, error) {
+	var rep trivyReport
+	if err := json.Unmarshal(report, &rep); err != nil {
+		return ScanSummary{}, fmt.Errorf("read trivy report: %w", err)
+	}
+	if rep.SchemaVersion != 2 {
+		return ScanSummary{}, fmt.Errorf("read trivy report: schema version %d, want 2", rep.SchemaVersion)
+	}
+	s := ScanSummary{Policy: policy, Counts: map[string]int{}, BlockingCounts: map[string]int{}}
+	var all []ScanFinding
+	blocks := func(id, sev string, fixable bool) bool {
+		return slices.Contains(policy.FailOn, sev) && (fixable || policy.FailUnfixed) && !slices.Contains(policy.Accept, id)
+	}
+	for _, res := range rep.Results {
+		s.Packages += len(res.Packages)
+		for _, v := range res.Vulnerabilities {
+			sev := severity(v.Severity)
+			all = append(all, ScanFinding{
+				ID: v.VulnerabilityID, Kind: FindingVulnerability, Severity: sev,
+				Package: v.PkgName, Installed: v.InstalledVersion, Fixed: v.FixedVersion,
+				Target: res.Target, Title: v.Title,
+				Blocking: blocks(v.VulnerabilityID, sev, v.FixedVersion != "" || v.Status == "fixed"),
+				Accepted: slices.Contains(policy.Accept, v.VulnerabilityID),
+			})
+		}
+		for _, sec := range res.Secrets {
+			sev := severity(sec.Severity)
+			all = append(all, ScanFinding{
+				ID: sec.RuleID, Kind: FindingSecret, Severity: sev,
+				Target: res.Target, Title: sec.Title,
+				Blocking: blocks(sec.RuleID, sev, true),
+				Accepted: slices.Contains(policy.Accept, sec.RuleID),
+			})
+		}
+	}
+	for _, f := range all {
+		s.Counts[f.Severity]++
+		if f.Blocking {
+			s.BlockingCounts[f.Severity]++
+			s.Blocked = true
+		}
+	}
+	sort.SliceStable(all, func(i, j int) bool {
+		a, b := all[i], all[j]
+		if a.Blocking != b.Blocking {
+			return a.Blocking
+		}
+		if ra, rb := slices.Index(Severities, a.Severity), slices.Index(Severities, b.Severity); ra != rb {
+			return ra < rb
+		}
+		if a.ID != b.ID {
+			return a.ID < b.ID
+		}
+		return a.Package < b.Package
+	})
+	s.Findings = all[:min(len(all), MaxSummaryFindings)]
+	if s.Findings == nil {
+		s.Findings = []ScanFinding{}
+	}
+	return s, nil
+}
+
+// severity normalizes a Trivy severity; anything unrecognised is UNKNOWN.
+func severity(s string) string {
+	s = strings.ToUpper(s)
+	if slices.Contains(Severities, s) {
+		return s
+	}
+	return "UNKNOWN"
+}
+
+// Reason is the one line a blocked build records as its error, naming the
+// blocking counts and the first few finding ids. It is empty when nothing blocks.
+func (s ScanSummary) Reason() string {
+	if !s.Blocked {
+		return ""
+	}
+	var counts []string
+	for _, sev := range Severities {
+		if n := s.BlockingCounts[sev]; n > 0 {
+			counts = append(counts, fmt.Sprintf("%d %s", n, sev))
+		}
+	}
+	var ids []string
+	for _, f := range s.Findings {
+		if !f.Blocking || len(ids) == 5 {
+			break
+		}
+		if !slices.Contains(ids, f.ID) {
+			ids = append(ids, f.ID)
+		}
+	}
+	total := 0
+	for _, n := range s.BlockingCounts {
+		total += n
+	}
+	list := strings.Join(ids, ", ")
+	if total > len(ids) {
+		list += fmt.Sprintf(" and %d more", total-len(ids))
+	}
+	return "the scan blocked the image: " + strings.Join(counts, ", ") + " (" + list + ")"
+}
+
+// ScanEnvelope is what scan-gate hands felis-api through its log.
+type ScanEnvelope struct {
+	Summary ScanSummary     `json:"summary"`
+	Report  json.RawMessage `json:"report,omitempty"`
+	SBOM    json.RawMessage `json:"sbom,omitempty"`
+}
+
+const (
+	envelopeBegin     = "felis-scan-envelope v1 begin"
+	envelopeEndPrefix = "felis-scan-envelope v1 end sha256="
+	envelopeLineWidth = 76
+)
+
+// MaxEnvelopeBytes bounds the gzip-compressed envelope. The kubelet rotates a
+// container log at 10 MiB by default, and a rotated-away half is gone from
+// GetLogs; base64 grows the payload by a third, so 6 MiB keeps the whole frame in
+// one file.
+const MaxEnvelopeBytes = 6 << 20
+
+// envelopeBudget is MaxEnvelopeBytes, shrunk by tests.
+var envelopeBudget = MaxEnvelopeBytes
+
+// maxEnvelopeJSON bounds the decompressed envelope a reader accepts.
+const maxEnvelopeJSON = 128 << 20
+
+// ErrNoScanEnvelope means a log holds no complete scan envelope.
+var ErrNoScanEnvelope = errors.New("build: no scan envelope in the log")
+
+// WriteScanEnvelope writes env to w as a framed block. When the compressed
+// envelope exceeds MaxEnvelopeBytes it drops the SBOM, then the report, and names
+// what it dropped in Summary.Omitted. It returns the envelope it wrote.
+func WriteScanEnvelope(w io.Writer, env ScanEnvelope) (ScanEnvelope, error) {
+	var payload []byte
+	for {
+		raw, err := json.Marshal(env)
+		if err != nil {
+			return env, err
+		}
+		var buf bytes.Buffer
+		zw := gzip.NewWriter(&buf)
+		if _, err := zw.Write(raw); err != nil {
+			return env, err
+		}
+		if err := zw.Close(); err != nil {
+			return env, err
+		}
+		payload = buf.Bytes()
+		if len(payload) <= envelopeBudget {
+			break
+		}
+		switch {
+		case env.SBOM != nil:
+			env.SBOM = nil
+			env.Summary.Omitted = append(env.Summary.Omitted, "sbom")
+		case env.Report != nil:
+			env.Report = nil
+			env.Summary.Omitted = append(env.Summary.Omitted, "report")
+		default:
+			return env, fmt.Errorf("build: scan summary alone compresses to %d bytes", len(payload))
+		}
+	}
+	sum := sha256.Sum256(payload)
+	enc := base64.StdEncoding.EncodeToString(payload)
+	bw := bufio.NewWriter(w)
+	fmt.Fprintln(bw, envelopeBegin)
+	for len(enc) > 0 {
+		n := min(len(enc), envelopeLineWidth)
+		fmt.Fprintln(bw, enc[:n])
+		enc = enc[n:]
+	}
+	fmt.Fprintln(bw, envelopeEndPrefix+hex.EncodeToString(sum[:]))
+	return env, bw.Flush()
+}
+
+// ReadScanEnvelope returns the last complete, intact envelope in a log. The
+// envelope scan-gate writes is the last thing it prints, so a frame that report
+// content managed to print earlier can never stand in for it.
+func ReadScanEnvelope(r io.Reader) (*ScanEnvelope, error) {
+	sc := bufio.NewScanner(r)
+	sc.Buffer(make([]byte, 64<<10), 1<<20)
+	var (
+		found   []byte
+		cur     strings.Builder
+		inFrame bool
+		budget  = envelopeBudget/3*4 + 4096
+	)
+	for sc.Scan() {
+		line := strings.TrimRight(sc.Text(), "\r")
+		switch {
+		case line == envelopeBegin:
+			inFrame = true
+			cur.Reset()
+		case inFrame && strings.HasPrefix(line, envelopeEndPrefix):
+			inFrame = false
+			payload, err := base64.StdEncoding.DecodeString(cur.String())
+			if err != nil {
+				continue
+			}
+			sum := sha256.Sum256(payload)
+			if hex.EncodeToString(sum[:]) == strings.TrimPrefix(line, envelopeEndPrefix) {
+				found = payload
+			}
+		case inFrame:
+			if cur.Len()+len(line) > budget {
+				inFrame = false
+				continue
+			}
+			cur.WriteString(line)
+		}
+	}
+	if err := sc.Err(); err != nil {
+		return nil, fmt.Errorf("build: read scan log: %w", err)
+	}
+	if found == nil {
+		return nil, ErrNoScanEnvelope
+	}
+	zr, err := gzip.NewReader(bytes.NewReader(found))
+	if err != nil {
+		return nil, fmt.Errorf("build: scan envelope: %w", err)
+	}
+	raw, err := io.ReadAll(io.LimitReader(zr, maxEnvelopeJSON+1))
+	if err != nil {
+		return nil, fmt.Errorf("build: scan envelope: %w", err)
+	}
+	if len(raw) > maxEnvelopeJSON {
+		return nil, fmt.Errorf("build: scan envelope exceeds %d bytes", maxEnvelopeJSON)
+	}
+	var env ScanEnvelope
+	if err := json.Unmarshal(raw, &env); err != nil {
+		return nil, fmt.Errorf("build: scan envelope: %w", err)
+	}
+	return &env, nil
+}
+
+// Scan is the scan record kept for one build: the verdict, and gzip copies of
+// the Trivy report and the CycloneDX SBOM (nil when the envelope left one out).
+type Scan struct {
+	BuildID   string      `json:"build_id"`
+	Summary   ScanSummary `json:"summary"`
+	ScannedAt time.Time   `json:"scanned_at"`
+	ReportGz  []byte      `json:"-"`
+	SBOMGz    []byte      `json:"-"`
+}
+
+// newScan compresses an envelope's documents into a Scan.
+func newScan(buildID string, env *ScanEnvelope, at time.Time) (Scan, error) {
+	s := Scan{BuildID: buildID, Summary: env.Summary, ScannedAt: at}
+	var err error
+	if s.ReportGz, err = gzipBytes(env.Report); err != nil {
+		return s, err
+	}
+	s.SBOMGz, err = gzipBytes(env.SBOM)
+	return s, err
+}
+
+func gzipBytes(b []byte) ([]byte, error) {
+	if len(b) == 0 {
+		return nil, nil
+	}
+	var buf bytes.Buffer
+	zw := gzip.NewWriter(&buf)
+	if _, err := zw.Write(b); err != nil {
+		return nil, err
+	}
+	if err := zw.Close(); err != nil {
+		return nil, err
+	}
+	return buf.Bytes(), nil
+}
+
+// Printable strips control characters from report text before a log line
+// carries it, so a package name from the scanned image cannot start a line of
+// its own (such as a forged envelope frame).
+func Printable(s string) string {
+	return strings.Map(func(r rune) rune {
+		if r < 0x20 || r == 0x7f || (r >= 0x80 && r < 0xa0) || r == '
' || r == '
' {
+			return '?'
+		}
+		return r
+	}, s)
+}
diff --git a/internal/build/scan_test.go b/internal/build/scan_test.go
new file mode 100644
index 0000000..1385513
--- /dev/null
+++ b/internal/build/scan_test.go
@@ -0,0 +1,383 @@
+package build
+
+import (
+	"bytes"
+	"compress/gzip"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+// trivyFixture is a trimmed Trivy 0.74 JSON report: an OS layer and a jar layer,
+// with fixed, unfixed and status-only-fixed vulnerabilities, a leaked secret and a
+// severity Trivy never assigns.
+const trivyFixture = `{
+  "SchemaVersion": 2,
+  "ArtifactName": "/image/image.tar",
+  "Results": [
+    {
+      "Target": "image.tar (ubuntu 24.04)",
+      "Class": "os-pkgs",
+      "Packages": [{"Name": "libc6"}, {"Name": "openssl"}, {"Name": "zlib1g"}],
+      "Vulnerabilities": [
+        {"VulnerabilityID": "CVE-2024-0003", "PkgName": "zlib1g", "InstalledVersion": "1.3", "FixedVersion": "1.3.1", "Status": "fixed", "Severity": "MEDIUM", "Title": "zlib overflow"},
+        {"VulnerabilityID": "CVE-2024-0002", "PkgName": "openssl", "InstalledVersion": "3.0.13", "FixedVersion": "", "Status": "affected", "Severity": "HIGH", "Title": "openssl timing"},
+        {"VulnerabilityID": "CVE-2024-0009", "PkgName": "libc6", "InstalledVersion": "2.39", "Status": "affected", "Severity": "bogus"}
+      ]
+    },
+    {
+      "Target": "data/mods/core.jar",
+      "Class": "lang-pkgs",
+      "Packages": [{"Name": "log4j-core"}, {"Name": "commons-text"}],
+      "Vulnerabilities": [
+        {"VulnerabilityID": "CVE-2024-0004", "PkgName": "commons-text", "InstalledVersion": "1.9", "Status": "fixed", "Severity": "HIGH"},
+        {"VulnerabilityID": "CVE-2024-0001", "PkgName": "log4j-core", "InstalledVersion": "2.14.1", "FixedVersion": "2.17.1", "Status": "fixed", "Severity": "CRITICAL", "Title": "Log4Shell"}
+      ]
+    },
+    {
+      "Target": "/data/server.properties",
+      "Class": "secret",
+      "Secrets": [{"RuleID": "aws-access-key-id", "Category": "AWS", "Severity": "CRITICAL", "Title": "AWS Access Key ID"}]
+    }
+  ]
+}`
+
+func findingIDs(fs []ScanFinding) []string {
+	var out []string
+	for _, f := range fs {
+		out = append(out, fmt.Sprintf("%s:%t", f.ID, f.Blocking))
+	}
+	return out
+}
+
+func TestParseSeverities(t *testing.T) {
+	for _, tc := range []struct {
+		in   string
+		want []string
+		err  string
+	}{
+		{in: "high, critical", want: []string{"CRITICAL", "HIGH"}},
+		{in: "LOW,medium,MEDIUM", want: []string{"MEDIUM", "LOW"}},
+		{in: "unknown", want: []string{"UNKNOWN"}},
+		{in: "HIGH,SEVERE", err: `unknown severity "SEVERE" (use CRITICAL, HIGH, MEDIUM, LOW, UNKNOWN)`},
+		{in: " , ", err: "no severity named"},
+	} {
+		got, err := ParseSeverities(tc.in)
+		if tc.err != "" {
+			if err == nil || err.Error() != tc.err {
+				t.Errorf("ParseSeverities(%q) err = %v, want %q", tc.in, err, tc.err)
+			}
+			continue
+		}
+		if err != nil || !reflect.DeepEqual(got, tc.want) {
+			t.Errorf("ParseSeverities(%q) = %v, %v; want %v", tc.in, got, err, tc.want)
+		}
+	}
+}
+
+func TestParseScanAccept(t *testing.T) {
+	got, err := ParseScanAccept(" CVE-2021-35515,GHSA-cfgp-2977-2fmm, ,aws-access-key-id,CVE-2021-35515,DLA-3782-1,RHSA-2024:1234")
+	if err != nil || !reflect.DeepEqual(got, []string{"CVE-2021-35515", "GHSA-cfgp-2977-2fmm", "aws-access-key-id", "DLA-3782-1", "RHSA-2024:1234"}) {
+		t.Errorf("ParseScanAccept = %v, %v", got, err)
+	}
+	if got, err := ParseScanAccept(""); err != nil || got != nil {
+		t.Errorf("empty = %v, %v; want nothing accepted", got, err)
+	}
+	for in, want := range map[string]string{
+		"CVE-2021-35515 CVE-2025-67030": `"CVE-2021-35515 CVE-2025-67030" is not a vulnerability id or secret rule id`,
+		"-rf":                           `"-rf" is not a vulnerability id or secret rule id`,
+		strings.Repeat("A", 129):        `"` + strings.Repeat("A", 129) + `" is not a vulnerability id or secret rule id`,
+	} {
+		if _, err := ParseScanAccept(in); err == nil || err.Error() != want {
+			t.Errorf("ParseScanAccept(%.20q) err = %v", in, err)
+		}
+	}
+	if got, err := ParseScanAccept(strings.Repeat("A", 128)); err != nil || len(got) != 1 {
+		t.Errorf("a 128-character id = %v, %v", got, err)
+	}
+}
+
+// An accepted id stays counted and listed, marked accepted, and never blocks;
+// the other findings are judged as before.
+func TestSummarizeAcceptedIDsNeverBlock(t *testing.T) {
+	s, err := Summarize([]byte(trivyFixture), ScanPolicy{FailOn: []string{"CRITICAL", "HIGH"},
+		Accept: []string{"CVE-2024-0001", "aws-access-key-id", "CVE-2099-0001"}})
+	if err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	var got []string
+	for _, f := range s.Findings {
+		got = append(got, fmt.Sprintf("%s:%t:%t", f.ID, f.Blocking, f.Accepted))
+	}
+	want := []string{"CVE-2024-0004:true:false", "CVE-2024-0001:false:true", "aws-access-key-id:false:true",
+		"CVE-2024-0002:false:false", "CVE-2024-0003:false:false", "CVE-2024-0009:false:false"}
+	if !reflect.DeepEqual(got, want) {
+		t.Errorf("findings = %v\nwant %v", got, want)
+	}
+	if !reflect.DeepEqual(s.Counts, map[string]int{"CRITICAL": 2, "HIGH": 2, "MEDIUM": 1, "UNKNOWN": 1}) ||
+		!reflect.DeepEqual(s.BlockingCounts, map[string]int{"HIGH": 1}) {
+		t.Errorf("counts = %v, blocking = %v", s.Counts, s.BlockingCounts)
+	}
+	if got := s.Reason(); got != "the scan blocked the image: 1 HIGH (CVE-2024-0004)" {
+		t.Errorf("reason = %q", got)
+	}
+	raw, err := json.Marshal(s.Policy)
+	if err != nil || string(raw) != `{"fail_on":["CRITICAL","HIGH"],"fail_unfixed":false,"accept":["CVE-2024-0001","aws-access-key-id","CVE-2099-0001"]}` {
+		t.Errorf("policy json = %s, %v", raw, err)
+	}
+}
+
+// A CRITICAL,HIGH policy blocks HIGH and CRITICAL findings that have a fixed release
+// (a FixedVersion, or Trivy's status "fixed"), and a leaked secret always.
+func TestSummarizeDefaultPolicy(t *testing.T) {
+	s, err := Summarize([]byte(trivyFixture), ScanPolicy{FailOn: []string{"CRITICAL", "HIGH"}})
+	if err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	if !s.Blocked || s.Packages != 5 {
+		t.Errorf("blocked=%t packages=%d, want true and 5", s.Blocked, s.Packages)
+	}
+	if want := map[string]int{"CRITICAL": 2, "HIGH": 2, "MEDIUM": 1, "UNKNOWN": 1}; !reflect.DeepEqual(s.Counts, want) {
+		t.Errorf("counts = %v, want %v", s.Counts, want)
+	}
+	if want := map[string]int{"CRITICAL": 2, "HIGH": 1}; !reflect.DeepEqual(s.BlockingCounts, want) {
+		t.Errorf("blocking counts = %v, want %v", s.BlockingCounts, want)
+	}
+	want := []string{"CVE-2024-0001:true", "aws-access-key-id:true", "CVE-2024-0004:true",
+		"CVE-2024-0002:false", "CVE-2024-0003:false", "CVE-2024-0009:false"}
+	if got := findingIDs(s.Findings); !reflect.DeepEqual(got, want) {
+		t.Errorf("findings = %v\nwant %v", got, want)
+	}
+	first := s.Findings[0]
+	if first != (ScanFinding{ID: "CVE-2024-0001", Kind: "vulnerability", Severity: "CRITICAL", Package: "log4j-core",
+		Installed: "2.14.1", Fixed: "2.17.1", Target: "data/mods/core.jar", Title: "Log4Shell", Blocking: true}) {
+		t.Errorf("first finding = %+v", first)
+	}
+	if sec := s.Findings[1]; sec.Kind != "secret" || sec.Target != "/data/server.properties" || sec.Title != "AWS Access Key ID" {
+		t.Errorf("secret finding = %+v", sec)
+	}
+	if got := s.Reason(); got != "the scan blocked the image: 2 CRITICAL, 1 HIGH (CVE-2024-0001, aws-access-key-id, CVE-2024-0004)" {
+		t.Errorf("reason = %q", got)
+	}
+}
+
+func TestSummarizePolicyVariants(t *testing.T) {
+	s, err := Summarize([]byte(trivyFixture), ScanPolicy{FailOn: []string{"CRITICAL", "HIGH"}, FailUnfixed: true})
+	if err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	if want := map[string]int{"CRITICAL": 2, "HIGH": 2}; !reflect.DeepEqual(s.BlockingCounts, want) {
+		t.Errorf("fail-unfixed blocking counts = %v, want %v", s.BlockingCounts, want)
+	}
+
+	s, err = Summarize([]byte(trivyFixture), ScanPolicy{FailOn: []string{"CRITICAL"}})
+	if err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	if got := s.Reason(); got != "the scan blocked the image: 2 CRITICAL (CVE-2024-0001, aws-access-key-id)" {
+		t.Errorf("CRITICAL-only reason = %q", got)
+	}
+
+	s, err = Summarize([]byte(trivyFixture), ScanPolicy{FailOn: []string{"LOW"}})
+	if err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	if s.Blocked || s.Reason() != "" || len(s.BlockingCounts) != 0 {
+		t.Errorf("LOW-only policy blocked=%t reason=%q counts=%v, want nothing blocking", s.Blocked, s.Reason(), s.BlockingCounts)
+	}
+}
+
+func TestSummarizeCleanAndBadReports(t *testing.T) {
+	s, err := Summarize([]byte(`{"SchemaVersion":2,"Results":[{"Target":"x","Packages":[{}]}]}`), ScanPolicy{FailOn: DefaultScanFailOn})
+	if err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	if s.Blocked || s.Packages != 1 || s.Findings == nil || len(s.Findings) != 0 {
+		t.Errorf("clean report = %+v, want unblocked, one package, an empty findings list", s)
+	}
+	if _, err := Summarize([]byte(`{"SchemaVersion":1,"Results":[]}`), ScanPolicy{}); err == nil ||
+		err.Error() != "read trivy report: schema version 1, want 2" {
+		t.Errorf("schema 1 err = %v", err)
+	}
+	if _, err := Summarize([]byte(`not json`), ScanPolicy{}); err == nil || !strings.HasPrefix(err.Error(), "read trivy report: ") {
+		t.Errorf("garbage err = %v", err)
+	}
+}
+
+// One CVE in two packages is two blocking findings under one id: the reason
+// names the id once and counts the other.
+func TestReasonNamesARepeatedIDOnce(t *testing.T) {
+	report := `{"SchemaVersion":2,"Results":[{"Target":"mods","Vulnerabilities":[
+	 {"VulnerabilityID":"CVE-2024-0001","PkgName":"log4j-core","InstalledVersion":"2.14.1","FixedVersion":"2.17.1","Severity":"CRITICAL"},
+	 {"VulnerabilityID":"CVE-2024-0001","PkgName":"log4j-api","InstalledVersion":"2.14.1","FixedVersion":"2.17.1","Severity":"CRITICAL"}]}]}`
+	s, err := Summarize([]byte(report), ScanPolicy{FailOn: DefaultScanFailOn})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := s.Reason(); got != "the scan blocked the image: 2 CRITICAL (CVE-2024-0001 and 1 more)" {
+		t.Errorf("reason = %q", got)
+	}
+}
+
+// A summary lists at most MaxSummaryFindings findings, while the counts and the
+// reason still cover every one.
+func TestSummarizeCapsTheListedFindings(t *testing.T) {
+	var vulns []string
+	for i := range 150 {
+		vulns = append(vulns, fmt.Sprintf(`{"VulnerabilityID":"CVE-2025-%04d","PkgName":"p","FixedVersion":"2","Severity":"HIGH"}`, i))
+	}
+	rep := `{"SchemaVersion":2,"Results":[{"Target":"t","Vulnerabilities":[` + strings.Join(vulns, ",") + `]}]}`
+	s, err := Summarize([]byte(rep), ScanPolicy{FailOn: []string{"CRITICAL", "HIGH"}})
+	if err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	if len(s.Findings) != 100 || s.Counts["HIGH"] != 150 || s.BlockingCounts["HIGH"] != 150 {
+		t.Errorf("listed %d, counted %d/%d; want 100 listed of 150", len(s.Findings), s.Counts["HIGH"], s.BlockingCounts["HIGH"])
+	}
+	if got := s.Reason(); got != "the scan blocked the image: 150 HIGH (CVE-2025-0000, CVE-2025-0001, CVE-2025-0002, CVE-2025-0003, CVE-2025-0004 and 145 more)" {
+		t.Errorf("reason = %q", got)
+	}
+}
+
+func TestScanEnvelopeRoundTripsThroughALog(t *testing.T) {
+	summary, err := Summarize([]byte(trivyFixture), ScanPolicy{FailOn: DefaultScanFailOn})
+	if err != nil {
+		t.Fatal(err)
+	}
+	sbom := json.RawMessage(`{"bomFormat":"CycloneDX","specVersion":"1.6","components":[{"name":"log4j-core","version":"2.14.1"}]}`)
+	var log bytes.Buffer
+	log.WriteString("felis scan-gate: 5 packages; findings: CRITICAL 2\n")
+	written, err := WriteScanEnvelope(&log, ScanEnvelope{Summary: summary, Report: json.RawMessage(trivyFixture), SBOM: sbom})
+	if err != nil {
+		t.Fatalf("WriteScanEnvelope: %v", err)
+	}
+	if written.Summary.Omitted != nil {
+		t.Errorf("a small envelope omitted %v", written.Summary.Omitted)
+	}
+	for _, line := range strings.Split(strings.TrimSpace(log.String()), "\n") {
+		if len(line) > 100 {
+			t.Errorf("log line of %d bytes: the frame must stay line-wrapped", len(line))
+		}
+	}
+	env, err := ReadScanEnvelope(strings.NewReader(log.String() + "trailing line\n"))
+	if err != nil {
+		t.Fatalf("ReadScanEnvelope: %v", err)
+	}
+	if !reflect.DeepEqual(env.Summary, summary) {
+		t.Errorf("summary came back as %+v", env.Summary)
+	}
+	var want, got bytes.Buffer
+	_ = json.Compact(&want, []byte(trivyFixture))
+	_ = json.Compact(&got, env.Report)
+	if got.String() != want.String() {
+		t.Errorf("report came back as %s", got.String())
+	}
+	if string(env.SBOM) != string(sbom) {
+		t.Errorf("sbom came back as %s", env.SBOM)
+	}
+}
+
+// The reader takes the last intact frame: scan-gate prints its envelope last, and
+// a frame whose checksum does not match is ignored.
+func TestReadScanEnvelopeTakesTheLastIntactFrame(t *testing.T) {
+	frame := func(blocked bool) string {
+		var b bytes.Buffer
+		if _, err := WriteScanEnvelope(&b, ScanEnvelope{Summary: ScanSummary{Blocked: blocked, Findings: []ScanFinding{}}}); err != nil {
+			t.Fatal(err)
+		}
+		return b.String()
+	}
+	env, err := ReadScanEnvelope(strings.NewReader(frame(false) + frame(true)))
+	if err != nil || !env.Summary.Blocked {
+		t.Errorf("two frames: got %+v, %v; want the second (blocked)", env, err)
+	}
+	broken := strings.Replace(frame(false), "sha256=", "sha256=00", 1)
+	env, err = ReadScanEnvelope(strings.NewReader(frame(true) + broken))
+	if err != nil || !env.Summary.Blocked {
+		t.Errorf("intact then broken: got %+v, %v; want the intact one", env, err)
+	}
+	if _, err := ReadScanEnvelope(strings.NewReader(broken)); !errors.Is(err, ErrNoScanEnvelope) {
+		t.Errorf("broken only: err = %v, want ErrNoScanEnvelope", err)
+	}
+	unterminated := strings.SplitAfter(frame(true), "\n")
+	if _, err := ReadScanEnvelope(strings.NewReader(strings.Join(unterminated[:len(unterminated)-2], ""))); !errors.Is(err, ErrNoScanEnvelope) {
+		t.Errorf("unterminated: err = %v, want ErrNoScanEnvelope", err)
+	}
+	if _, err := ReadScanEnvelope(strings.NewReader("fake logs")); !errors.Is(err, ErrNoScanEnvelope) {
+		t.Errorf("no frame: err = %v, want ErrNoScanEnvelope", err)
+	}
+}
+
+// An envelope past the budget drops the SBOM first, then the report, and says so.
+func TestWriteScanEnvelopeDropsWhatDoesNotFit(t *testing.T) {
+	defer func(old int) { envelopeBudget = old }(envelopeBudget)
+	envelopeBudget = 2048
+	noise := func(n int) json.RawMessage {
+		// Incompressible enough: a JSON string of pseudo-random hex.
+		var b strings.Builder
+		b.WriteString(`"`)
+		x := uint32(2463534242)
+		for range n {
+			x ^= x << 13
+			x ^= x >> 17
+			x ^= x << 5
+			fmt.Fprintf(&b, "%08x", x)
+		}
+		b.WriteString(`"`)
+		return json.RawMessage(b.String())
+	}
+	base := ScanSummary{Findings: []ScanFinding{}}
+	for _, tc := range []struct {
+		name         string
+		report, sbom json.RawMessage
+		omitted      []string
+	}{
+		{"sbom too big", json.RawMessage(`{"r":1}`), noise(1000), []string{"sbom"}},
+		{"both too big", noise(1000), noise(1000), []string{"sbom", "report"}},
+	} {
+		var log bytes.Buffer
+		written, err := WriteScanEnvelope(&log, ScanEnvelope{Summary: base, Report: tc.report, SBOM: tc.sbom})
+		if err != nil {
+			t.Fatalf("%s: %v", tc.name, err)
+		}
+		env, err := ReadScanEnvelope(&log)
+		if err != nil {
+			t.Fatalf("%s: read: %v", tc.name, err)
+		}
+		if !reflect.DeepEqual(written.Summary.Omitted, tc.omitted) || !reflect.DeepEqual(env.Summary.Omitted, tc.omitted) {
+			t.Errorf("%s: omitted %v / read back %v, want %v", tc.name, written.Summary.Omitted, env.Summary.Omitted, tc.omitted)
+		}
+		if env.SBOM != nil || (len(tc.omitted) == 2) != (env.Report == nil) {
+			t.Errorf("%s: read back report=%d sbom=%d bytes", tc.name, len(env.Report), len(env.SBOM))
+		}
+	}
+}
+
+func TestNewScanCompressesTheDocuments(t *testing.T) {
+	sc, err := newScan("bld-7", &ScanEnvelope{Summary: ScanSummary{Blocked: true}, Report: json.RawMessage(`{"SchemaVersion":2}`)}, testNow)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if sc.BuildID != "bld-7" || !sc.Summary.Blocked || !sc.ScannedAt.Equal(testNow) || sc.SBOMGz != nil {
+		t.Errorf("scan = %+v", sc)
+	}
+	zr, err := gzip.NewReader(bytes.NewReader(sc.ReportGz))
+	if err != nil {
+		t.Fatal(err)
+	}
+	raw, _ := io.ReadAll(zr)
+	if string(raw) != `{"SchemaVersion":2}` {
+		t.Errorf("report decompresses to %q", raw)
+	}
+}
+
+func TestPrintableStripsLineBreaks(t *testing.T) {
+	got := Printable("evil\nfelis-scan-envelope v1 begin\r\x1b[31m
x\u0085y")
+	if got != "evil?felis-scan-envelope v1 begin??[31m?x?y" {
+		t.Errorf("Printable = %q", got)
+	}
+}
diff --git a/internal/config/config.go b/internal/config/config.go
index 91e4513..2a81c5d 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -16,6 +16,10 @@ import (
 	"github.com/BurntSushi/toml"
 )
 
+// scanIDPattern is build.scanIDPattern: the shape of a finding id scan-gate
+// takes in its comma-separated --accept flag.
+var scanIDPattern = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9._:-]{0,127}$`)
+
 // Config is the parsed felis.toml.
 type Config struct {
 	Server   ServerConfig   `toml:"server"`
@@ -220,6 +224,16 @@ type RegistryConfig struct {
 	// vulnerability DB: <url>/mirror/trivy-java-db:1 by default. Empty keeps that
 	// default.
 	TrivyJavaDBRepository string `toml:"trivy_java_db_repository"`
+	// ScanFailOn lists the severities that block a built image (CRITICAL, HIGH,
+	// MEDIUM, LOW, UNKNOWN). Empty keeps CRITICAL (build.DefaultScanFailOn).
+	ScanFailOn []string `toml:"scan_fail_on"`
+	// ScanFailUnfixed blocks on vulnerabilities that have no fixed release too.
+	// Off by default: the submitter cannot upgrade past them, and the build's
+	// scan report still lists them.
+	ScanFailUnfixed bool `toml:"scan_fail_unfixed"`
+	// ScanAccept lists vulnerability ids and secret rule ids accepted as known
+	// risks (build.ScanPolicy.Accept): still listed in the scan, never blocking.
+	ScanAccept []string `toml:"scan_accept"`
 	// UserUploadsContext is the object-store base under which a user-submitted
 	// modpack's Kaniko build context is pinned. It belongs to the §16 build
 	// subsystem's input domain (the build-context store), introduced by the
@@ -564,6 +578,22 @@ func (c *Config) Validate() error {
 	if n := c.Registry.MaxConcurrentBuilds; n < 0 || n > 6 {
 		return fmt.Errorf("config: [registry] max_concurrent_builds %d must be 1-6 (0 keeps 2)", n)
 	}
+	for i, sev := range c.Registry.ScanFailOn {
+		sev = strings.ToUpper(strings.TrimSpace(sev))
+		c.Registry.ScanFailOn[i] = sev
+		switch sev {
+		case "CRITICAL", "HIGH", "MEDIUM", "LOW", "UNKNOWN":
+		default:
+			return fmt.Errorf("config: [registry] scan_fail_on %q must be one of CRITICAL, HIGH, MEDIUM, LOW, UNKNOWN", sev)
+		}
+	}
+	for i, id := range c.Registry.ScanAccept {
+		id = strings.TrimSpace(id)
+		c.Registry.ScanAccept[i] = id
+		if !scanIDPattern.MatchString(id) {
+			return fmt.Errorf("config: [registry] scan_accept %q must be a vulnerability id or secret rule id (letters, digits, and . _ : -)", id)
+		}
+	}
 	// [smtp] is optional as a whole, but once a host is named the block must be
 	// deliverable: a From address (relays reject MAIL FROM:<>) and a sane port.
 	// Fail at load, not at the first OTP a player is waiting on.
diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index a9e6293..60cb089 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -250,6 +250,52 @@ url = "`+url+`"
 	}
 }
 
+// The scan policy reaches the build Job as written, case aside, and a severity
+// Trivy does not use fails the load instead of every build.
+func TestLoadScanPolicy(t *testing.T) {
+	cfg, err := config.Load(writeTOML(t, `
+[server]
+root_domain = "mc.example.net"
+[database]
+url = "postgres://felis@db/felis"
+[registry]
+scan_fail_on = ["critical", " High "]
+scan_fail_unfixed = true
+scan_accept = [" CVE-2021-35515 ", "aws-access-key-id"]
+`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := strings.Join(cfg.Registry.ScanFailOn, ","); got != "CRITICAL,HIGH" || !cfg.Registry.ScanFailUnfixed {
+		t.Errorf("scan policy = %q, unfixed %t", got, cfg.Registry.ScanFailUnfixed)
+	}
+	if got := strings.Join(cfg.Registry.ScanAccept, ","); got != "CVE-2021-35515,aws-access-key-id" {
+		t.Errorf("scan_accept = %q", got)
+	}
+	_, err = config.Load(writeTOML(t, `
+[server]
+root_domain = "mc.example.net"
+[database]
+url = "postgres://felis@db/felis"
+[registry]
+scan_accept = ["CVE-2021-35515,CVE-2025-67030"]
+`))
+	if err == nil || err.Error() != `config: [registry] scan_accept "CVE-2021-35515,CVE-2025-67030" must be a vulnerability id or secret rule id (letters, digits, and . _ : -)` {
+		t.Errorf("err = %v", err)
+	}
+	_, err = config.Load(writeTOML(t, `
+[server]
+root_domain = "mc.example.net"
+[database]
+url = "postgres://felis@db/felis"
+[registry]
+scan_fail_on = ["HIGH", "SEVERE"]
+`))
+	if err == nil || err.Error() != `config: [registry] scan_fail_on "SEVERE" must be one of CRITICAL, HIGH, MEDIUM, LOW, UNKNOWN` {
+		t.Errorf("err = %v", err)
+	}
+}
+
 // TestLoadAuthSourcesPreservesOrder pins the Felis-nano priority contract: the
 // [[auth_source]] array-of-tables decodes in file order (config order = priority), which
 // is why it is an array-of-tables and not a map. A map keyed by tag would load and pass
diff --git a/internal/pgint/pgint_test.go b/internal/pgint/pgint_test.go
index 8a04b72..10c6b18 100644
--- a/internal/pgint/pgint_test.go
+++ b/internal/pgint/pgint_test.go
@@ -1502,6 +1502,74 @@ func TestBuildStoreContract(t *testing.T) {
 	}
 }
 
+// A build's scan round-trips whole (the summary as jsonb, the documents as
+// bytea, a missing SBOM as NULL), a rescan replaces it, it cannot exist without
+// its build, and it goes when the build row does.
+func TestBuildStoreScans(t *testing.T) {
+	ctx := context.Background()
+	s := build.NewPGStore(db)
+	id := "bld-scan-" + suffix(t)
+	if err := s.CreateBuild(ctx, &build.Build{ID: id, ImageRef: "registry.felis.svc:5000/user-uploads/" + id + ":latest",
+		Status: build.StatusPending, RequestedBy: "pgint"}); err != nil {
+		t.Fatalf("CreateBuild: %v", err)
+	}
+	if _, err := s.GetScan(ctx, id); !errors.Is(err, build.ErrNotFound) {
+		t.Fatalf("scan before one was saved = %v, want ErrNotFound", err)
+	}
+	at := time.Date(2026, 9, 20, 10, 0, 0, 0, time.UTC)
+	first := build.Scan{BuildID: id, ScannedAt: at, ReportGz: []byte{0x1f, 0x8b, 0x01}, Summary: build.ScanSummary{
+		Policy: build.ScanPolicy{FailOn: []string{"CRITICAL", "HIGH"}}, Blocked: true, Packages: 7,
+		Counts: map[string]int{"CRITICAL": 1}, BlockingCounts: map[string]int{"CRITICAL": 1},
+		Findings: []build.ScanFinding{{ID: "CVE-2024-0001", Kind: "vulnerability", Severity: "CRITICAL",
+			Package: "log4j-core", Installed: "2.14.1", Fixed: "2.17.1", Target: "mods/core.jar", Blocking: true}},
+		Omitted: []string{"sbom"},
+	}}
+	if err := s.SaveScan(ctx, first); err != nil {
+		t.Fatalf("SaveScan: %v", err)
+	}
+	got, err := s.GetScan(ctx, id)
+	if err != nil {
+		t.Fatalf("GetScan: %v", err)
+	}
+	if !got.ScannedAt.Equal(at) || string(got.ReportGz) != "\x1f\x8b\x01" || got.SBOMGz != nil {
+		t.Errorf("scan = at %v, report %x, sbom %x", got.ScannedAt, got.ReportGz, got.SBOMGz)
+	}
+	sum := got.Summary
+	if !sum.Blocked || sum.Packages != 7 || sum.Counts["CRITICAL"] != 1 || sum.BlockingCounts["CRITICAL"] != 1 ||
+		strings.Join(sum.Policy.FailOn, ",") != "CRITICAL,HIGH" || strings.Join(sum.Omitted, ",") != "sbom" ||
+		len(sum.Findings) != 1 || sum.Findings[0].Fixed != "2.17.1" || !sum.Findings[0].Blocking {
+		t.Errorf("summary = %+v", sum)
+	}
+	var blocked bool
+	if err := db.QueryRowContext(ctx, `SELECT blocked FROM image_build_scans WHERE build_id = $1`, id).Scan(&blocked); err != nil || !blocked {
+		t.Errorf("blocked column = %v (%v), want true", blocked, err)
+	}
+
+	rescan := build.Scan{BuildID: id, ScannedAt: at.Add(time.Hour), ReportGz: []byte{0x02}, SBOMGz: []byte{0x03},
+		Summary: build.ScanSummary{Policy: build.ScanPolicy{FailOn: []string{"CRITICAL"}}, Packages: 7,
+			Counts: map[string]int{}, BlockingCounts: map[string]int{}, Findings: []build.ScanFinding{}}}
+	if err := s.SaveScan(ctx, rescan); err != nil {
+		t.Fatalf("SaveScan (rescan): %v", err)
+	}
+	got, _ = s.GetScan(ctx, id)
+	if got.Summary.Blocked || !got.ScannedAt.Equal(at.Add(time.Hour)) || string(got.SBOMGz) != "\x03" || len(got.Summary.Findings) != 0 {
+		t.Errorf("rescan = %+v", got)
+	}
+	if err := db.QueryRowContext(ctx, `SELECT blocked FROM image_build_scans WHERE build_id = $1`, id).Scan(&blocked); err != nil || blocked {
+		t.Errorf("blocked column after a passing rescan = %v (%v), want false", blocked, err)
+	}
+
+	if err := s.SaveScan(ctx, build.Scan{BuildID: "bld-none-" + suffix(t), ScannedAt: at}); err == nil {
+		t.Error("a scan saved for a build that does not exist")
+	}
+	if _, err := db.ExecContext(ctx, `DELETE FROM image_builds WHERE id = $1`, id); err != nil {
+		t.Fatalf("delete build: %v", err)
+	}
+	if _, err := s.GetScan(ctx, id); !errors.Is(err, build.ErrNotFound) {
+		t.Errorf("scan after its build was deleted = %v, want ErrNotFound", err)
+	}
+}
+
 // ListBuilds pages newest first across every requester, finds a build by part of
 // its ref (any case), its id or its status, and leaves the Dockerfile out.
 func TestBuildStoreListBuilds(t *testing.T) {
diff --git a/internal/store/migrations/0032_image_build_scans.sql b/internal/store/migrations/0032_image_build_scans.sql
new file mode 100644
index 0000000..67b58e6
--- /dev/null
+++ b/internal/store/migrations/0032_image_build_scans.sql
@@ -0,0 +1,13 @@
+-- The scan record of each build: scan-gate's verdict, the full Trivy JSON
+-- report and the CycloneDX SBOM (both gzip), read back from the build pod's log
+-- when the Job finishes. A blocked build keeps the findings that blocked it; an
+-- admitted image keeps its SBOM, reached from image_whitelist.build_id. The row
+-- goes with its build.
+CREATE TABLE image_build_scans (
+  build_id text PRIMARY KEY REFERENCES image_builds(id) ON DELETE CASCADE,
+  blocked boolean NOT NULL,
+  summary jsonb NOT NULL,
+  report_gz bytea,
+  sbom_gz bytea,
+  scanned_at timestamptz NOT NULL
+);
diff --git a/panel/dev/mockApi.ts b/panel/dev/mockApi.ts
index cd9c4b7..4d75c3f 100644
--- a/panel/dev/mockApi.ts
+++ b/panel/dev/mockApi.ts
@@ -6,6 +6,7 @@ import type {
   AutostartPolicy,
   BackupView,
   Build,
+  BuildScan,
   CreateServerRequest,
   FleetServer,
   Identity,
@@ -337,7 +338,7 @@ function initialState(): MockState {
         id: "bld-2",
         image_ref: "registry.felis.svc:5000/forge-broken:1.0",
         status: "failed",
-        error: "trivy found a CRITICAL CVE: CVE-2026-12345 in library/forge",
+        error: "the scan blocked the image: 1 CRITICAL, 1 HIGH (CVE-2026-12345, CVE-2025-24813)",
         requested_by: "owner@mock.felis.local",
         created_at: new Date(Date.now() - 1800000).toISOString(),
         finished_at: new Date(Date.now() - 1700000).toISOString(),
@@ -529,6 +530,57 @@ function server(
   };
 }
 
+// mockScan is the scan build.Builder.Scan would keep for the seeded builds.
+function mockScan(b: Build): BuildScan | null {
+  const at = b.finished_at ?? b.created_at;
+  if (b.id === "bld-2") {
+    return {
+      build_id: b.id, scanned_at: at, has_report: true, has_sbom: false,
+      summary: {
+        policy: { fail_on: ["CRITICAL", "HIGH"], fail_unfixed: false, accept: ["CVE-2021-35515", "CVE-2025-67030"] },
+        blocked: true, packages: 214,
+        counts: { CRITICAL: 1, HIGH: 4, MEDIUM: 6, LOW: 2 },
+        blocking_counts: { CRITICAL: 1, HIGH: 1 },
+        omitted: ["sbom"],
+        findings: [
+          { id: "CVE-2026-12345", kind: "vulnerability", severity: "CRITICAL", package: "net.minecraftforge:forge",
+            installed: "47.1.0", fixed: "47.1.3", target: "libraries/net/minecraftforge/forge/47.1.0/forge.jar", blocking: true },
+          { id: "CVE-2025-24813", kind: "vulnerability", severity: "HIGH", package: "org.apache.tomcat.embed:tomcat-embed-core",
+            installed: "9.0.97", fixed: "9.0.99, 10.1.35", target: "mods/webmap-2.4.jar", blocking: true },
+          { id: "CVE-2021-35515", kind: "vulnerability", severity: "HIGH", package: "org.apache.commons:commons-compress",
+            installed: "1.5", fixed: "1.21", target: "paper/paper.jar", blocking: false, accepted: true },
+          { id: "CVE-2024-6763", kind: "vulnerability", severity: "HIGH", package: "org.eclipse.jetty:jetty-http",
+            installed: "9.4.53.v20231009", target: "mods/webmap-2.4.jar", blocking: false },
+          { id: "CVE-2023-2976", kind: "vulnerability", severity: "HIGH", package: "com.google.guava:guava",
+            installed: "31.1-jre", target: "libraries/com/google/guava/guava/31.1-jre/guava-31.1-jre.jar", blocking: false },
+          { id: "CVE-2024-47554", kind: "vulnerability", severity: "MEDIUM", package: "commons-io:commons-io",
+            installed: "2.11.0", fixed: "2.14.0", target: "libraries/commons-io/commons-io/2.11.0/commons-io-2.11.0.jar", blocking: false },
+          { id: "CVE-2020-8908", kind: "vulnerability", severity: "LOW", package: "com.google.guava:guava",
+            installed: "31.1-jre", fixed: "32.0.0-android", target: "libraries/com/google/guava/guava/31.1-jre/guava-31.1-jre.jar", blocking: false },
+        ],
+      },
+    };
+  }
+  if (b.id === "bld-1") {
+    return {
+      build_id: b.id, scanned_at: at, has_report: true, has_sbom: true,
+      summary: {
+        policy: { fail_on: ["CRITICAL"], fail_unfixed: false },
+        blocked: false, packages: 187,
+        counts: { MEDIUM: 1, LOW: 1 },
+        blocking_counts: {},
+        findings: [
+          { id: "CVE-2024-47554", kind: "vulnerability", severity: "MEDIUM", package: "commons-io:commons-io",
+            installed: "2.11.0", fixed: "2.14.0", target: "libraries/commons-io/commons-io/2.11.0/commons-io-2.11.0.jar", blocking: false },
+          { id: "CVE-2020-8908", kind: "vulnerability", severity: "LOW", package: "com.google.guava:guava",
+            installed: "31.1-jre", fixed: "32.0.0-android", target: "libraries/com/google/guava/guava/31.1-jre/guava-31.1-jre.jar", blocking: false },
+        ],
+      },
+    };
+  }
+  return null;
+}
+
 function sendJSON(res: ServerResponse, status: number, value: unknown): void {
   res.statusCode = status;
   res.setHeader("Content-Type", "application/json");
@@ -1665,6 +1717,44 @@ async function handleImageRoute(ctx: SessionContext): Promise<boolean> {
     return true;
   }
 
+  // GET /api/v1/images/build/{id}/scan, /scan/report, /sbom (the kept scan). The
+  // seeded builds bld-1 (passed) and bld-2 (blocked) have one; the older history
+  // ran before builds kept their scans.
+  if (
+    is("GET", ctx) && ctx.parts[3] === "build" && ctx.parts[4] &&
+    ((ctx.parts[5] === "scan" && (ctx.parts.length === 6 || (ctx.parts[6] === "report" && ctx.parts.length === 7))) ||
+      (ctx.parts[5] === "sbom" && ctx.parts.length === 6))
+  ) {
+    if (!isAdmin(ctx.account.role)) {
+      sendError(ctx.res, 403, "forbidden", "admin account required");
+      return true;
+    }
+    const build = ctx.state.builds.find((b) => b.id === ctx.parts[4]);
+    const scan = build ? mockScan(build) : null;
+    if (!build || !scan) {
+      sendError(ctx.res, 404, "scan_not_found",
+        "this build has no scan: it has not reached the scan step, or it ran before builds kept their scans");
+      return true;
+    }
+    if (ctx.parts.length === 6 && ctx.parts[5] === "scan") {
+      sendJSON(ctx.res, 200, scan);
+      return true;
+    }
+    const sbom = ctx.parts[5] === "sbom";
+    if (sbom && !scan.has_sbom) {
+      sendError(ctx.res, 404, "scan_document_not_kept",
+        "this build's scan kept no SBOM: it was too large to keep, or the step that writes it failed");
+      return true;
+    }
+    ctx.res.statusCode = 200;
+    ctx.res.setHeader("Content-Type", sbom ? "application/vnd.cyclonedx+json" : "application/json");
+    ctx.res.setHeader("Content-Disposition", `attachment; filename="${build.id}${sbom ? ".cdx.json" : "-trivy.json"}"`);
+    ctx.res.end(JSON.stringify(sbom
+      ? { bomFormat: "CycloneDX", specVersion: "1.6", components: [] }
+      : { SchemaVersion: 2, ArtifactName: build.image_ref, Results: [] }, null, 2));
+    return true;
+  }
+
   // POST /api/v1/images/build/{id}/cancel (cancel build)
   if (is("POST", ctx) && ctx.parts[3] === "build" && ctx.parts[5] === "cancel" && ctx.parts.length === 6) {
     if (!isAdmin(ctx.account.role)) {
diff --git a/panel/src/i18n/resources/en-US/admin.json b/panel/src/i18n/resources/en-US/admin.json
index 247ccf2..32f9324 100644
--- a/panel/src/i18n/resources/en-US/admin.json
+++ b/panel/src/i18n/resources/en-US/admin.json
@@ -45,7 +45,7 @@
   "build_status_failed": "Failed",
   "build_status_cancelled": "Cancelled",
   "build_queued_hint": "The concurrent build limit ([registry] max_concurrent_builds) is reached; this build starts on its own when an earlier one finishes.",
-  "view_logs_btn": "Logs",
+  "view_logs_btn": "Scan & logs",
   "cancel_build_btn": "Cancel",
   "no_builds_title": "No Builds Found",
   "no_builds_hint": "You can trigger your first image build task using the form on the top right.",
@@ -238,5 +238,36 @@
   "trigger_build_desc": "Enter the build parameters to launch a Kaniko pipeline job in an isolated namespace.",
   "builds_search_placeholder": "Search build ID, image reference, or status...",
   "builds_refresh_failed": "Couldn't refresh the build list: {{reason}}",
-  "build_requested_by_you": "You"
+  "build_requested_by_you": "You",
+  "scan_title": "Security scan",
+  "scan_blocked": "Blocked",
+  "scan_passed": "Passed",
+  "scan_loading": "Loading the security scan…",
+  "scan_none": "No security scan was kept for this build. It stopped before the scan step, or it ran before builds kept their scans.",
+  "scan_load_failed": "Couldn't load the security scan: {{reason}}",
+  "scan_meta_one": "Scanned {{when}} · {{count}} package",
+  "scan_meta_other": "Scanned {{when}} · {{count}} packages",
+  "scan_policy": "Blocks on {{severities}}; vulnerabilities with no fixed release are listed only",
+  "scan_policy_unfixed": "Blocks on {{severities}}, including vulnerabilities with no fixed release",
+  "scan_counts_label": "Findings by severity",
+  "scan_blocking_count_one": "{{count}} blocks the image",
+  "scan_blocking_count_other": "{{count}} block the image",
+  "scan_clean": "Trivy found nothing to report in this image.",
+  "scan_showing": "Showing {{shown}} of {{total}} findings. The full report lists every one.",
+  "scan_col_id": "ID",
+  "scan_col_severity": "Severity",
+  "scan_col_package": "Package",
+  "scan_col_version": "Installed → fixed",
+  "scan_col_target": "Found in",
+  "scan_no_fix": "no fix yet",
+  "scan_blocks": "Blocks",
+  "scan_policy_accepts_one": "{{count}} ID accepted as a known risk",
+  "scan_policy_accepts_other": "{{count}} IDs accepted as known risks",
+  "scan_accepted": "Accepted",
+  "scan_accepted_title": "Listed in [registry] scan_accept as a known risk, so it never blocks.",
+  "scan_secret": "Secret: {{title}}",
+  "scan_download_report": "Trivy report",
+  "scan_download_sbom": "SBOM",
+  "scan_not_kept": "Not kept with this build: the file was too large, or the step that writes it failed.",
+  "scan_download_failed": "Couldn't download: {{reason}}"
 }
diff --git a/panel/src/i18n/resources/zh-CN/admin.json b/panel/src/i18n/resources/zh-CN/admin.json
index c942d6e..d8bb13f 100644
--- a/panel/src/i18n/resources/zh-CN/admin.json
+++ b/panel/src/i18n/resources/zh-CN/admin.json
@@ -45,7 +45,7 @@
   "build_status_failed": "失败",
   "build_status_cancelled": "已取消",
   "build_queued_hint": "同时运行的构建已达上限（[registry] max_concurrent_builds），这个构建会在前面的构建结束后自动开始。",
-  "view_logs_btn": "日志",
+  "view_logs_btn": "扫描与日志",
   "cancel_build_btn": "取消",
   "no_builds_title": "暂无构建任务",
   "no_builds_hint": "您可以使用右上角表单触发第一个镜像构建任务。",
@@ -238,5 +238,33 @@
   "trigger_build_desc": "输入镜像构建参数，在隔离命名空间中启动 Kaniko 流水线任务。",
   "builds_search_placeholder": "搜索构建 ID、镜像引用或状态...",
   "builds_refresh_failed": "构建列表刷新失败：{{reason}}",
-  "build_requested_by_you": "你"
+  "build_requested_by_you": "你",
+  "scan_title": "安全扫描",
+  "scan_blocked": "已拦截",
+  "scan_passed": "已通过",
+  "scan_loading": "正在读取安全扫描…",
+  "scan_none": "这次构建没有留存安全扫描：它在扫描步骤前就结束了，或者早于开始留存扫描的版本。",
+  "scan_load_failed": "读取安全扫描失败：{{reason}}",
+  "scan_meta_other": "扫描于 {{when}} · {{count}} 个软件包",
+  "scan_policy": "拦截级别 {{severities}}；尚无修复版本的漏洞只列出",
+  "scan_policy_unfixed": "拦截级别 {{severities}}，尚无修复版本的漏洞同样拦截",
+  "scan_counts_label": "按严重度统计的发现",
+  "scan_blocking_count_other": "其中 {{count}} 项拦截镜像",
+  "scan_clean": "Trivy 在这个镜像里没有发现任何问题。",
+  "scan_showing": "显示 {{total}} 项中的 {{shown}} 项，完整报告列出全部发现。",
+  "scan_col_id": "编号",
+  "scan_col_severity": "严重度",
+  "scan_col_package": "软件包",
+  "scan_col_version": "已装 → 修复版本",
+  "scan_col_target": "所在位置",
+  "scan_no_fix": "暂无修复",
+  "scan_blocks": "拦截",
+  "scan_policy_accepts_other": "{{count}} 个 ID 已作为已知风险接受",
+  "scan_accepted": "已接受",
+  "scan_accepted_title": "已列入 [registry] scan_accept 作为已知风险，不会拦截。",
+  "scan_secret": "密钥：{{title}}",
+  "scan_download_report": "Trivy 报告",
+  "scan_download_sbom": "SBOM",
+  "scan_not_kept": "这次构建未留存该文件：文件过大，或生成它的步骤失败。",
+  "scan_download_failed": "下载失败：{{reason}}"
 }
diff --git a/panel/src/lib/api.test.ts b/panel/src/lib/api.test.ts
index ad40c1d..7e58b61 100644
--- a/panel/src/lib/api.test.ts
+++ b/panel/src/lib/api.test.ts
@@ -548,6 +548,38 @@ describe("image whitelist and builds wire shapes", () => {
       expect(String(url)).toBe("/submissions/sub-1/context");
     });
 
+    it("getBuildScan GETs the kept scan, and downloadBuildScanDocument saves each document under its own name", async () => {
+      const fetchSpy = fakeFetch({ build_id: "bld-7", has_report: true, has_sbom: true });
+      vi.stubGlobal("fetch", fetchSpy);
+      await api.getBuildScan("bld-7");
+      expect(String((fetchSpy as unknown as ReturnType<typeof vi.fn>).mock.calls[0][0])).toBe("/images/build/bld-7/scan");
+
+      const docFetch = vi.fn(async () => ({
+        ok: true,
+        status: 200,
+        statusText: "OK",
+        headers: new Headers(),
+        blob: async () => new Blob(["{}"]),
+      })) as unknown as typeof fetch;
+      vi.stubGlobal("fetch", docFetch);
+      vi.spyOn(URL, "createObjectURL").mockReturnValue("blob:doc");
+      vi.spyOn(URL, "revokeObjectURL").mockImplementation(() => {});
+      const links: { href: string; download: string; click: () => void }[] = [];
+      vi.stubGlobal("document", {
+        createElement: () => {
+          const link = { href: "", download: "", click: vi.fn() };
+          links.push(link);
+          return link;
+        },
+      });
+      await api.downloadBuildScanDocument("bld-7", "report");
+      await api.downloadBuildScanDocument("bld-7", "sbom");
+      const urls = (docFetch as unknown as ReturnType<typeof vi.fn>).mock.calls.map(([u]) => String(u));
+      expect(urls).toEqual(["/images/build/bld-7/scan/report", "/images/build/bld-7/sbom"]);
+      expect(links.map((l) => l.download)).toEqual(["bld-7-trivy.json", "bld-7.cdx.json"]);
+      expect(links.every((l) => (l.click as ReturnType<typeof vi.fn>).mock.calls.length === 1)).toBe(true);
+    });
+
     it("rejectSubmission POSTs {reason} to /submissions/{id}/reject", async () => {
       const sub = { id: "sub-1", status: "rejected", reject_reason: "bad" };
       const fetchSpy = fakeFetch(sub);
diff --git a/panel/src/lib/api.ts b/panel/src/lib/api.ts
index 10f73ad..b76d9a5 100644
--- a/panel/src/lib/api.ts
+++ b/panel/src/lib/api.ts
@@ -5,6 +5,7 @@ import type {
   BackupView,
   BanlistResult,
   Build,
+  BuildScan,
   CreateServerRequest,
   CreateUserRequest,
   FleetServer,
@@ -454,6 +455,25 @@ export const api = rejectingSync({
   cancelBuild: (id: string) =>
     request<Build>("POST", urlPath`/images/build/${id}/cancel`),
 
+  /** What the build's scan gate kept; 404 scan_not_found before the scan step. */
+  getBuildScan: (id: string) =>
+    request<BuildScan>("GET", urlPath`/images/build/${id}/scan`),
+
+  /** Saves the build's full Trivy report or CycloneDX SBOM. The bytes name the
+   *  image's own packages and paths, so they are downloaded, never rendered. */
+  downloadBuildScanDocument: async (id: string, doc: "report" | "sbom") => {
+    const res = await fetchOK(
+      doc === "report" ? urlPath`/images/build/${id}/scan/report` : urlPath`/images/build/${id}/sbom`,
+      { method: "GET" },
+    );
+    const url = URL.createObjectURL(await res.blob());
+    const link = document.createElement("a");
+    link.href = url;
+    link.download = doc === "report" ? `${id}-trivy.json` : `${id}.cdx.json`;
+    link.click();
+    URL.revokeObjectURL(url);
+  },
+
   createServer: (req: CreateServerRequest) =>
     request<{ name: string; subdomain: string; desiredState: string }>(
       "POST",
diff --git a/panel/src/lib/openapi.gen.ts b/panel/src/lib/openapi.gen.ts
index 9282e13..2544b75 100644
--- a/panel/src/lib/openapi.gen.ts
+++ b/panel/src/lib/openapi.gen.ts
@@ -1976,6 +1976,57 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/api/v1/images/build/{id}/scan": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        /** The scan gate's verdict and findings for a build (admin). */
+        get: operations["getBuildScan"];
+        put?: never;
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
+    "/api/v1/images/build/{id}/scan/report": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        /** Download a build's full Trivy JSON report (admin). */
+        get: operations["getBuildScanReport"];
+        put?: never;
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
+    "/api/v1/images/build/{id}/sbom": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        /** Download a build's CycloneDX SBOM (admin). */
+        get: operations["getBuildSBOM"];
+        put?: never;
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/api/v1/images": {
         parameters: {
             query?: never;
@@ -2289,6 +2340,64 @@ export interface components {
              */
             finished_at?: string;
         };
+        /** @description What a build's scan gate kept (GET /api/v1/images/build/{id}/scan): its verdict under the policy it ran with, the listed findings, and which full documents can be downloaded. */
+        BuildScan: {
+            build_id: string;
+            /** Format: date-time */
+            scanned_at: string;
+            summary: components["schemas"]["ScanSummary"];
+            /** @description The full Trivy JSON report is kept (GET .../scan/report). */
+            has_report: boolean;
+            /** @description The CycloneDX SBOM is kept (GET .../sbom). */
+            has_sbom: boolean;
+        };
+        /** @description The verdict scan-gate reached on one Trivy report (internal/build ScanSummary). */
+        ScanSummary: {
+            policy: components["schemas"]["ScanPolicy"];
+            /** @description A finding blocked the image, so it was never pushed. */
+            blocked: boolean;
+            /** @description Packages Trivy found in the image. */
+            packages: number;
+            /** @description Every finding by severity (CRITICAL, HIGH, MEDIUM, LOW, UNKNOWN); a severity with none is absent. */
+            counts: {
+                [key: string]: number;
+            };
+            /** @description The findings the policy blocks on, by severity. */
+            blocking_counts: {
+                [key: string]: number;
+            };
+            /** @description Blocking findings first, then the rest, most severe first; at most 100. The downloadable report lists all of them. */
+            findings: components["schemas"]["ScanFinding"][];
+            /** @description Documents (report, sbom) too large to keep with the build. Omitted when none. */
+            omitted?: ("report" | "sbom")[];
+        };
+        /** @description Which findings block an image ([registry] scan_fail_on / scan_fail_unfixed / scan_accept). */
+        ScanPolicy: {
+            fail_on: ("CRITICAL" | "HIGH" | "MEDIUM" | "LOW" | "UNKNOWN")[];
+            /** @description A vulnerability with no fixed release blocks too. */
+            fail_unfixed: boolean;
+            /** @description Vulnerability ids and secret rule ids accepted as known risks; findings under them never block. Omitted when none. */
+            accept?: string[];
+        };
+        /** @description One vulnerability or leaked secret (internal/build ScanFinding). */
+        ScanFinding: {
+            /** @description The CVE/GHSA id, or the secret rule id. */
+            id: string;
+            /** @enum {string} */
+            kind: "vulnerability" | "secret";
+            /** @enum {string} */
+            severity: "CRITICAL" | "HIGH" | "MEDIUM" | "LOW" | "UNKNOWN";
+            package?: string;
+            installed?: string;
+            /** @description The first release that fixes it. Omitted when none exists. */
+            fixed?: string;
+            /** @description The file or layer Trivy found it in. */
+            target: string;
+            title?: string;
+            blocking: boolean;
+            /** @description The policy accepts this id, so it never blocks. Omitted when false. */
+            accepted?: boolean;
+        };
         /** @description One whitelisted image (internal/build Image). */
         Image: {
             image_ref: string;
@@ -7506,6 +7615,108 @@ export interface operations {
             503: components["responses"]["ServiceUnavailable"];
         };
     };
+    getBuildScan: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path: {
+                id: string;
+            };
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description The kept scan. */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["BuildScan"];
+                };
+            };
+            401: components["responses"]["Unauthorized"];
+            403: components["responses"]["Forbidden"];
+            /** @description No scan for this build (scan_not_found) — it has not reached the scan step, or it ran before builds kept their scans. */
+            404: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["Error"];
+                };
+            };
+            503: components["responses"]["ServiceUnavailable"];
+        };
+    };
+    getBuildScanReport: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path: {
+                id: string;
+            };
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description The Trivy report (SchemaVersion 2), served as the attachment <id>-trivy.json. */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": Record<string, never>;
+                };
+            };
+            401: components["responses"]["Unauthorized"];
+            403: components["responses"]["Forbidden"];
+            /** @description No scan for this build (scan_not_found), or the report was too large to keep (scan_document_not_kept). */
+            404: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["Error"];
+                };
+            };
+            503: components["responses"]["ServiceUnavailable"];
+        };
+    };
+    getBuildSBOM: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path: {
+                id: string;
+            };
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description The CycloneDX JSON SBOM, served as the attachment <id>.cdx.json. */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/vnd.cyclonedx+json": Record<string, never>;
+                };
+            };
+            401: components["responses"]["Unauthorized"];
+            403: components["responses"]["Forbidden"];
+            /** @description No scan for this build (scan_not_found), or the SBOM was too large to keep or its step failed (scan_document_not_kept). */
+            404: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["Error"];
+                };
+            };
+            503: components["responses"]["ServiceUnavailable"];
+        };
+    };
     listImages: {
         parameters: {
             query?: never;
diff --git a/panel/src/lib/types.parity.ts b/panel/src/lib/types.parity.ts
index 918ae25..792ef7d 100644
--- a/panel/src/lib/types.parity.ts
+++ b/panel/src/lib/types.parity.ts
@@ -37,6 +37,10 @@ export type WireParity = [
   Holds<Parity<T.FleetServer, S["FleetServer"]>>,
   Holds<Parity<T.BackupView, S["BackupView"]>>,
   Holds<Parity<T.Build, S["Build"]>>,
+  Holds<Parity<T.BuildScan, S["BuildScan"]>>,
+  Holds<Parity<T.ScanSummary, S["ScanSummary"]>>,
+  Holds<Parity<T.ScanPolicy, S["ScanPolicy"]>>,
+  Holds<Parity<T.ScanFinding, S["ScanFinding"]>>,
   Holds<Parity<T.WhitelistImage, S["Image"]>>,
   Holds<Parity<T.Submission, S["Submission"]>>,
   Holds<Parity<T.UserView, S["UserView"]>>,
diff --git a/panel/src/lib/types.ts b/panel/src/lib/types.ts
index df1ab02..0b557b1 100644
--- a/panel/src/lib/types.ts
+++ b/panel/src/lib/types.ts
@@ -310,6 +310,53 @@ export interface Build {
   context_digest?: string;
 }
 
+export type ScanSeverity = "CRITICAL" | "HIGH" | "MEDIUM" | "LOW" | "UNKNOWN";
+
+/** ScanFinding mirrors build.ScanFinding — one vulnerability or leaked secret. */
+export interface ScanFinding {
+  id: string;
+  kind: "vulnerability" | "secret";
+  severity: ScanSeverity;
+  package?: string;
+  installed?: string;
+  /** The first release that fixes it; absent when none exists. */
+  fixed?: string;
+  target: string;
+  title?: string;
+  blocking: boolean;
+  /** The policy accepts this id, so it never blocks; absent when false. */
+  accepted?: boolean;
+}
+
+/** ScanPolicy mirrors build.ScanPolicy ([registry] scan_fail_on / scan_fail_unfixed / scan_accept). */
+export interface ScanPolicy {
+  fail_on: ScanSeverity[];
+  fail_unfixed: boolean;
+  /** Finding ids accepted as known risks; absent when none. */
+  accept?: string[];
+}
+
+/** ScanSummary mirrors build.ScanSummary — the verdict scan-gate reached. */
+export interface ScanSummary {
+  policy: ScanPolicy;
+  blocked: boolean;
+  packages: number;
+  counts: Record<string, number>;
+  blocking_counts: Record<string, number>;
+  /** Blocking first, then most severe first; at most 100. */
+  findings: ScanFinding[];
+  omitted?: ("report" | "sbom")[];
+}
+
+/** BuildScan is GET /images/build/{id}/scan. */
+export interface BuildScan {
+  build_id: string;
+  scanned_at: string;
+  summary: ScanSummary;
+  has_report: boolean;
+  has_sbom: boolean;
+}
+
 export type SubmissionStatus = "pending_review" | "approved" | "rejected";
 
 /** Submission mirrors an image_submissions row (spec §6, migration 0002). */
diff --git a/panel/src/pages/admin/BuildScanPanel.test.tsx b/panel/src/pages/admin/BuildScanPanel.test.tsx
new file mode 100644
index 0000000..b1f219a
--- /dev/null
+++ b/panel/src/pages/admin/BuildScanPanel.test.tsx
@@ -0,0 +1,173 @@
+// @vitest-environment jsdom
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { render, screen, within } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { BuildScanPanel } from "./BuildScanPanel";
+import type { Build, BuildScan } from "@/lib/types";
+
+const calls = vi.hoisted(() => ({
+  getBuildScan: vi.fn(),
+  downloadBuildScanDocument: vi.fn(),
+}));
+vi.mock("@/lib/config", () => ({ loadConfig: () => Promise.resolve({}) }));
+vi.mock("@/lib/api", async (importOriginal) => {
+  const actual = await importOriginal<typeof import("@/lib/api")>();
+  return { ...actual, api: { ...actual.api, ...calls } };
+});
+
+const FAILED: Build = {
+  id: "bld-7",
+  image_ref: "registry.felis.svc:5000/user-uploads/s-1:latest",
+  status: "failed",
+  requested_by: "owner@example.test",
+  created_at: "2026-09-20T09:58:00Z",
+  finished_at: "2026-09-20T10:00:00Z",
+};
+
+// Two blocking findings (a fixable CRITICAL and a leaked key), a fixable HIGH the
+// policy accepts, one unfixed HIGH that only gets listed, and two more findings
+// past the listed ones.
+const BLOCKED: BuildScan = {
+  build_id: "bld-7",
+  scanned_at: "2026-09-20T10:00:00Z",
+  has_report: true,
+  has_sbom: false,
+  summary: {
+    policy: { fail_on: ["CRITICAL", "HIGH"], fail_unfixed: false, accept: ["CVE-2021-35515"] },
+    blocked: true,
+    packages: 12,
+    counts: { CRITICAL: 2, HIGH: 2, MEDIUM: 2 },
+    blocking_counts: { CRITICAL: 2 },
+    findings: [
+      { id: "CVE-2024-0001", kind: "vulnerability", severity: "CRITICAL", package: "log4j-core",
+        installed: "2.14.1", fixed: "2.17.1", target: "mods/core.jar", blocking: true },
+      { id: "aws-access-key-id", kind: "secret", severity: "CRITICAL", target: "config/keys.txt",
+        title: "AWS Access Key ID", blocking: true },
+      { id: "CVE-2021-35515", kind: "vulnerability", severity: "HIGH", package: "org.apache.commons:commons-compress",
+        installed: "1.5", fixed: "1.21", target: "paper/paper.jar", blocking: false, accepted: true },
+      { id: "CVE-2024-0002", kind: "vulnerability", severity: "HIGH", package: "openssl",
+        installed: "3.0.13", target: "usr/lib/libssl.so.3", blocking: false },
+    ],
+  },
+};
+
+const CLEAN: BuildScan = {
+  build_id: "bld-8",
+  scanned_at: "2026-09-20T10:00:00Z",
+  has_report: true,
+  has_sbom: true,
+  summary: {
+    policy: { fail_on: ["HIGH"], fail_unfixed: true },
+    blocked: false,
+    packages: 1,
+    counts: {},
+    blocking_counts: {},
+    findings: [],
+  },
+};
+
+beforeEach(() => {
+  for (const fn of Object.values(calls)) fn.mockReset();
+});
+afterEach(() => {
+  vi.restoreAllMocks();
+});
+
+describe("BuildScanPanel", () => {
+  it("shows what blocked the image, the listed findings, and how many more the report holds", async () => {
+    calls.getBuildScan.mockResolvedValue(BLOCKED);
+    render(<BuildScanPanel build={FAILED} />);
+    const panel = await screen.findByRole("region", { name: "Security scan" });
+    expect(calls.getBuildScan).toHaveBeenCalledWith("bld-7");
+    expect(within(panel).getByText("Blocked")).toBeTruthy();
+    expect(panel.textContent).toContain(
+      "· 12 packages · Blocks on CRITICAL, HIGH; vulnerabilities with no fixed release are listed only · 1 ID accepted as a known risk",
+    );
+    expect(within(panel).getByText("1 ID accepted as a known risk").getAttribute("title")).toBe("CVE-2021-35515");
+
+    const chips = within(within(panel).getByRole("list", { name: "Findings by severity" })).getAllByRole("listitem");
+    expect(chips.map((c) => c.textContent)).toEqual(["CRITICAL2", "HIGH2", "MEDIUM2", "LOW0", "UNKNOWN0"]);
+    expect(chips[0].getAttribute("title")).toBe("2 block the image");
+    expect(chips[1].getAttribute("title")).toBeNull();
+
+    const cve = within(panel).getByText("CVE-2024-0001").closest("li")!;
+    expect(cve.textContent).toBe("CVE-2024-0001BlocksCRITICALlog4j-core2.14.1 → 2.17.1mods/core.jar");
+    const secret = within(panel).getByText("aws-access-key-id").closest("li")!;
+    expect(secret.textContent).toBe("aws-access-key-idBlocksCRITICALSecret: AWS Access Key ID—config/keys.txt");
+    const accepted = within(panel).getByText("CVE-2021-35515").closest("li")!;
+    expect(accepted.textContent).toBe("CVE-2021-35515AcceptedHIGHorg.apache.commons:commons-compress1.5 → 1.21paper/paper.jar");
+    expect(within(accepted).getByText("Accepted").getAttribute("title")).toBe(
+      "Listed in [registry] scan_accept as a known risk, so it never blocks.",
+    );
+    const unfixed = within(panel).getByText("CVE-2024-0002").closest("li")!;
+    expect(unfixed.textContent).toBe("CVE-2024-0002HIGHopenssl3.0.13 → no fix yetusr/lib/libssl.so.3");
+    expect(within(panel).getByText("Showing 4 of 6 findings. The full report lists every one.")).toBeTruthy();
+  });
+
+  it("downloads the report it kept and explains the SBOM it did not", async () => {
+    calls.getBuildScan.mockResolvedValue(BLOCKED);
+    calls.downloadBuildScanDocument.mockResolvedValue(undefined);
+    render(<BuildScanPanel build={FAILED} />);
+    const panel = await screen.findByRole("region", { name: "Security scan" });
+    const sbom = within(panel).getByRole("button", { name: "SBOM" }) as HTMLButtonElement;
+    expect(sbom.disabled).toBe(true);
+    expect(sbom.getAttribute("title")).toBe(
+      "Not kept with this build: the file was too large, or the step that writes it failed.",
+    );
+    await userEvent.click(within(panel).getByRole("button", { name: "Trivy report" }));
+    expect(calls.downloadBuildScanDocument).toHaveBeenCalledWith("bld-7", "report");
+
+    calls.downloadBuildScanDocument.mockRejectedValue({
+      status: 404,
+      code: "scan_document_not_kept",
+      message: "this build's scan kept no report: it was too large to keep, or the step that writes it failed",
+    });
+    await userEvent.click(within(panel).getByRole("button", { name: "Trivy report" }));
+    expect((await within(panel).findByRole("alert")).textContent).toBe(
+      "Couldn't download: this build's scan kept no report: it was too large to keep, or the step that writes it failed",
+    );
+  });
+
+  it("says a clean scan found nothing and names the stricter policy it ran under", async () => {
+    calls.getBuildScan.mockResolvedValue(CLEAN);
+    render(<BuildScanPanel build={{ ...FAILED, id: "bld-8", status: "succeeded" }} />);
+    const panel = await screen.findByRole("region", { name: "Security scan" });
+    expect(within(panel).getByText("Passed")).toBeTruthy();
+    expect(panel.textContent).toContain("· 1 package · Blocks on HIGH, including vulnerabilities with no fixed release");
+    expect(panel.textContent).not.toContain("accepted");
+    expect(within(panel).getByText("Trivy found nothing to report in this image.")).toBeTruthy();
+    expect(within(panel).queryByText("Found in")).toBeNull();
+    calls.downloadBuildScanDocument.mockResolvedValue(undefined);
+    await userEvent.click(within(panel).getByRole("button", { name: "SBOM" }));
+    expect(calls.downloadBuildScanDocument).toHaveBeenCalledWith("bld-8", "sbom");
+  });
+
+  it("says when a build kept no scan, and retries a scan that failed to load", async () => {
+    calls.getBuildScan.mockRejectedValue({ status: 404, code: "scan_not_found", message: "this build has no scan" });
+    const { unmount } = render(<BuildScanPanel build={FAILED} />);
+    expect(
+      await screen.findByText(
+        "No security scan was kept for this build. It stopped before the scan step, or it ran before builds kept their scans.",
+      ),
+    ).toBeTruthy();
+    unmount();
+
+    calls.getBuildScan.mockRejectedValueOnce({ status: 500, code: "internal", message: "database is away" });
+    calls.getBuildScan.mockResolvedValueOnce(BLOCKED);
+    render(<BuildScanPanel build={FAILED} />);
+    expect((await screen.findByRole("alert")).textContent).toBe(
+      "Couldn't load the security scan: The service is unavailable right now (it may be restarting or upgrading). Try again shortly.",
+    );
+    await userEvent.click(screen.getByRole("button", { name: "Try again" }));
+    expect(await screen.findByRole("region", { name: "Security scan" })).toBeTruthy();
+    expect(screen.queryByRole("alert")).toBeNull();
+  });
+
+  it("asks nothing for a build that is still running or was cancelled", () => {
+    const { container, rerender } = render(<BuildScanPanel build={{ ...FAILED, status: "building" }} />);
+    rerender(<BuildScanPanel build={{ ...FAILED, status: "cancelled" }} />);
+    rerender(<BuildScanPanel build={{ ...FAILED, status: "pending" }} />);
+    expect(container.textContent).toBe("");
+    expect(calls.getBuildScan).not.toHaveBeenCalled();
+  });
+});
diff --git a/panel/src/pages/admin/BuildScanPanel.tsx b/panel/src/pages/admin/BuildScanPanel.tsx
new file mode 100644
index 0000000..5863066
--- /dev/null
+++ b/panel/src/pages/admin/BuildScanPanel.tsx
@@ -0,0 +1,259 @@
+import { useCallback, useState } from "react";
+import { Download, ShieldAlert, ShieldCheck } from "lucide-react";
+import { useTranslation } from "react-i18next";
+import { Badge } from "@/components/ui/badge";
+import { Button } from "@/components/ui/button";
+import { MessageLine } from "@/components/MessageLine";
+import { api, humanizeError } from "@/lib/api";
+import { formatAbsolute, formatRelative } from "@/lib/format";
+import { useAsync } from "@/lib/hooks";
+import { cn } from "@/lib/utils";
+import type { Build, BuildScan, ScanFinding, ScanSeverity } from "@/lib/types";
+
+const SEVERITIES: ScanSeverity[] = ["CRITICAL", "HIGH", "MEDIUM", "LOW", "UNKNOWN"];
+
+const SEVERITY_STYLE: Record<ScanSeverity, string> = {
+  CRITICAL: "bg-rose-500/10 text-rose-500 border-rose-500/25",
+  HIGH: "bg-orange-500/10 text-orange-500 border-orange-500/25",
+  MEDIUM: "bg-amber-500/10 text-amber-500 border-amber-500/25",
+  LOW: "bg-sky-500/10 text-sky-500 border-sky-500/25",
+  UNKNOWN: "bg-zinc-500/10 text-zinc-400 border-zinc-500/25",
+};
+
+const GRID = "md:grid md:grid-cols-[minmax(0,10rem)_5.5rem_minmax(0,1fr)_minmax(0,11rem)_minmax(0,1fr)] md:gap-3";
+
+/** The scan a finished build's scan gate kept: its verdict under the policy it
+ *  ran with, the findings, and the full Trivy report and SBOM to download. A
+ *  build still running or cancelled has none, so nothing is fetched for it. */
+export function BuildScanPanel({ build }: { build: Build }) {
+  const scanned = build.status === "succeeded" || build.status === "failed";
+  if (!scanned) return null;
+  return <ScanView buildId={build.id} />;
+}
+
+function ScanView({ buildId }: { buildId: string }) {
+  const { t } = useTranslation("admin");
+  const load = useCallback(() => api.getBuildScan(buildId), [buildId]);
+  const { data: scan, error, loading, reload } = useAsync(load, [load]);
+
+  if (scan === null && loading) {
+    return <p className="mt-3 text-[11px] text-muted-foreground">{t("scan_loading")}</p>;
+  }
+  if (scan === null && error) {
+    if ((error as { code?: string }).code === "scan_not_found") {
+      return (
+        <p className="mt-3 rounded-md border border-dashed border-border px-3 py-2 text-[11px] text-muted-foreground">
+          {t("scan_none")}
+        </p>
+      );
+    }
+    return (
+      <div className="mt-3 flex flex-wrap items-center gap-2">
+        <MessageLine kind="error" message={t("scan_load_failed", { reason: humanizeError(error) })} className="flex-1" />
+        <Button variant="outline" size="sm" onClick={reload}>
+          {t("common:try_again")}
+        </Button>
+      </div>
+    );
+  }
+  if (scan === null) return null;
+  return <ScanReport scan={scan} />;
+}
+
+function ScanReport({ scan }: { scan: BuildScan }) {
+  const { t, i18n } = useTranslation("admin");
+  const locale = i18n.language;
+  const [downloadError, setDownloadError] = useState<string | null>(null);
+  const [downloading, setDownloading] = useState<"report" | "sbom" | null>(null);
+  const s = scan.summary;
+  const total = SEVERITIES.reduce((n, sev) => n + (s.counts[sev] ?? 0), 0);
+  const Icon = s.blocked ? ShieldAlert : ShieldCheck;
+
+  const download = async (doc: "report" | "sbom") => {
+    setDownloading(doc);
+    setDownloadError(null);
+    try {
+      await api.downloadBuildScanDocument(scan.build_id, doc);
+    } catch (e) {
+      setDownloadError(t("scan_download_failed", { reason: humanizeError(e) }));
+    } finally {
+      setDownloading(null);
+    }
+  };
+
+  return (
+    <section
+      aria-label={t("scan_title")}
+      className={cn(
+        "mt-3 rounded-lg border p-3 space-y-3",
+        s.blocked ? "border-rose-500/30 bg-rose-500/[0.03]" : "border-emerald-500/25 bg-emerald-500/[0.03]",
+      )}
+    >
+      <div className="flex flex-wrap items-start gap-x-3 gap-y-2">
+        <Icon className={cn("h-4 w-4 mt-0.5 shrink-0", s.blocked ? "text-rose-500" : "text-emerald-500")} />
+        <div className="min-w-0 flex-1 space-y-0.5">
+          <div className="flex flex-wrap items-center gap-2">
+            <h3 className="text-xs font-semibold text-foreground">{t("scan_title")}</h3>
+            <Badge
+              variant="outline"
+              className={cn(
+                "px-1.5 py-0 text-[10px] font-semibold uppercase tracking-wider",
+                s.blocked
+                  ? "bg-rose-500/10 text-rose-500 border-rose-500/20"
+                  : "bg-emerald-500/10 text-emerald-500 border-emerald-500/20",
+              )}
+            >
+              {s.blocked ? t("scan_blocked") : t("scan_passed")}
+            </Badge>
+          </div>
+          <p className="text-[11px] text-muted-foreground">
+            <span title={formatAbsolute(scan.scanned_at, locale)}>
+              {t("scan_meta", { when: formatRelative(scan.scanned_at, Date.now(), locale), count: s.packages })}
+            </span>
+            {" · "}
+            {t(s.policy.fail_unfixed ? "scan_policy_unfixed" : "scan_policy", {
+              severities: s.policy.fail_on.join(", "),
+            })}
+            {s.policy.accept && s.policy.accept.length > 0 && (
+              <>
+                {" · "}
+                <span title={s.policy.accept.join(", ")} className="underline decoration-dotted underline-offset-2">
+                  {t("scan_policy_accepts", { count: s.policy.accept.length })}
+                </span>
+              </>
+            )}
+          </p>
+        </div>
+        {/* Narrow screens: the downloads take their own line under the text. */}
+        <div className="flex w-full flex-wrap items-center gap-1.5 pl-7 sm:w-auto sm:pl-0">
+          <DownloadButton
+            label={t("scan_download_report")}
+            kept={scan.has_report}
+            busy={downloading === "report"}
+            onClick={() => download("report")}
+          />
+          <DownloadButton
+            label={t("scan_download_sbom")}
+            kept={scan.has_sbom}
+            busy={downloading === "sbom"}
+            onClick={() => download("sbom")}
+          />
+        </div>
+      </div>
+
+      <ul className="flex flex-wrap gap-1.5" aria-label={t("scan_counts_label")}>
+        {SEVERITIES.map((sev) => {
+          const n = s.counts[sev] ?? 0;
+          const blocking = s.blocking_counts[sev] ?? 0;
+          return (
+            <li
+              key={sev}
+              title={blocking > 0 ? t("scan_blocking_count", { count: blocking }) : undefined}
+              className={cn(
+                "flex items-center gap-1.5 rounded border px-2 py-0.5 font-mono text-[10px] font-semibold",
+                n > 0 ? SEVERITY_STYLE[sev] : "border-border text-muted-foreground/60",
+                blocking > 0 && "ring-1 ring-current",
+              )}
+            >
+              <span>{sev}</span>
+              <span>{n}</span>
+            </li>
+          );
+        })}
+      </ul>
+
+      {downloadError && <MessageLine kind="error" message={downloadError} compact />}
+
+      {total === 0 ? (
+        <p className="text-[11px] text-muted-foreground">{t("scan_clean")}</p>
+      ) : (
+        <div className="rounded-md border border-border bg-background/60">
+          <div className={cn("hidden px-3 py-2 text-[10px] font-semibold text-muted-foreground border-b", GRID)}>
+            <div>{t("scan_col_id")}</div>
+            <div>{t("scan_col_severity")}</div>
+            <div>{t("scan_col_package")}</div>
+            <div>{t("scan_col_version")}</div>
+            <div>{t("scan_col_target")}</div>
+          </div>
+          <ul className="max-h-72 overflow-y-auto divide-y divide-border">
+            {s.findings.map((f, i) => (
+              <FindingRow key={`${f.id}-${f.package ?? ""}-${f.target}-${i}`} finding={f} />
+            ))}
+          </ul>
+          {total > s.findings.length && (
+            <p className="border-t border-border px-3 py-2 text-[10px] text-muted-foreground">
+              {t("scan_showing", { shown: s.findings.length, total })}
+            </p>
+          )}
+        </div>
+      )}
+    </section>
+  );
+}
+
+function FindingRow({ finding: f }: { finding: ScanFinding }) {
+  const { t } = useTranslation("admin");
+  const secret = f.kind === "secret";
+  return (
+    <li className={cn("px-3 py-2 text-[11px] flex flex-wrap items-center gap-x-3 gap-y-1", GRID, f.blocking && "bg-rose-500/[0.04]")}>
+      <div className="flex min-w-0 items-center gap-1.5">
+        <span className="font-mono font-medium text-foreground select-all truncate" title={f.id}>{f.id}</span>
+        {f.blocking && (
+          <span className="shrink-0 rounded bg-rose-500/15 px-1 text-[9px] font-bold uppercase tracking-wide text-rose-500">
+            {t("scan_blocks")}
+          </span>
+        )}
+        {f.accepted && (
+          <span
+            title={t("scan_accepted_title")}
+            className="shrink-0 rounded bg-zinc-500/15 px-1 text-[9px] font-bold uppercase tracking-wide text-muted-foreground"
+          >
+            {t("scan_accepted")}
+          </span>
+        )}
+      </div>
+      <div>
+        <span className={cn("rounded border px-1.5 py-px font-mono text-[9px] font-semibold", SEVERITY_STYLE[f.severity])}>
+          {f.severity}
+        </span>
+      </div>
+      <div className="w-full min-w-0 truncate md:w-auto" title={secret ? f.title : f.package}>
+        {secret ? t("scan_secret", { title: f.title ?? f.id }) : <span className="font-mono">{f.package}</span>}
+      </div>
+      <div className="min-w-0 truncate font-mono text-muted-foreground">
+        {secret ? "—" : (
+          <>
+            {f.installed}
+            {" → "}
+            {f.fixed ? <span className="text-emerald-500">{f.fixed}</span> : <span className="italic">{t("scan_no_fix")}</span>}
+          </>
+        )}
+      </div>
+      <div className="w-full min-w-0 truncate font-mono text-[10px] text-muted-foreground md:w-auto" title={f.target}>
+        {f.target}
+      </div>
+    </li>
+  );
+}
+
+function DownloadButton({ label, kept, busy, onClick }: {
+  label: string;
+  kept: boolean;
+  busy: boolean;
+  onClick: () => void;
+}) {
+  const { t } = useTranslation("admin");
+  return (
+    <Button
+      variant="outline"
+      size="sm"
+      className="h-7 gap-1 px-2 text-[11px]"
+      disabled={!kept || busy}
+      title={kept ? undefined : t("scan_not_kept")}
+      onClick={onClick}
+    >
+      <Download className="h-3 w-3" />
+      {label}
+    </Button>
+  );
+}
diff --git a/panel/src/pages/admin/ImageBuildPage.tsx b/panel/src/pages/admin/ImageBuildPage.tsx
index 4d0b85d..20d8167 100644
--- a/panel/src/pages/admin/ImageBuildPage.tsx
+++ b/panel/src/pages/admin/ImageBuildPage.tsx
@@ -28,6 +28,7 @@ import { Pagination } from "@/components/Pagination";
 import { api, buildLogsStreamURL, humanizeError } from "@/lib/api";
 import { formatRelative, formatAbsolute } from "@/lib/format";
 import { useAsync, useConfig } from "@/lib/hooks";
+import { BuildScanPanel } from "./BuildScanPanel";
 import { useTier } from "@/lib/tier";
 import type { Build, BuildStatus, Submission } from "@/lib/types";
 
@@ -522,11 +523,14 @@ export function ImageBuildPage() {
                       </div>
                     </div>
 
-                    {/* Inline SSE Log Console */}
+                    {/* The scan gate's verdict, then the inline SSE log console */}
                     {activeLogBuildId === b.id && (
-                      <div className="mt-3 h-[300px] flex flex-col">
-                        <LogConsole url={buildLogsStreamURL(config.apiBase, b.id)} />
-                      </div>
+                      <>
+                        <BuildScanPanel build={b} />
+                        <div className="mt-3 h-[300px] flex flex-col">
+                          <LogConsole url={buildLogsStreamURL(config.apiBase, b.id)} />
+                        </div>
+                      </>
                     )}
                   </li>
                 ))}