diff --git a/.github/workflows/bridge-gate.yml b/.github/workflows/bridge-gate.yml
index eda0d039..234b0e3a 100644
--- a/.github/workflows/bridge-gate.yml
+++ b/.github/workflows/bridge-gate.yml
@@ -17,9 +17,9 @@
 # Notes for review:
 #  - B2 (major -> review) is left to the existing human-review path; it can be added
 #    later via dependabot/fetch-metadata.
-#  - panic-attack is built from source (public clone). Production hardening: a released
-#    binary, or -- to match estate convention -- a hyperpolymath/standards reusable
-#    workflow. Offered as a follow-up.
+#  - panic-attack is built at the commit that static-analysis-gate.yml pins in
+#    PANIC_ATTACK_REF. That file owns the pin: this job reads it, so the two
+#    workflows cannot use different scanners and no moving ref is built (#481).
 #  - github context is passed via env: only (no ${{ }} in run lines) per estate rules.
 name: bridge-gate
 on:
@@ -44,21 +44,45 @@ jobs:
             exit 1
           fi
 
-      - name: Build panic-attack (Patch-Bridge)
+      - name: Build panic-attack at the Static Analysis Gate pin (Patch-Bridge)
         run: |
-          git clone --depth 1 https://github.com/hyperpolymath/panic-attack /tmp/pa
-          cargo build --release --features http --manifest-path /tmp/pa/Cargo.toml
-          echo "/tmp/pa/target/release" >> "$GITHUB_PATH"
+          set -euo pipefail
+          # One pin for both workflows. A missing or floating value builds nothing.
+          ref=$(yq -r '.env.PANIC_ATTACK_REF' .github/workflows/static-analysis-gate.yml)
+          if ! [[ "$ref" =~ ^[0-9a-f]{40}$ ]]; then
+            echo "::error::static-analysis-gate.yml has no full-SHA PANIC_ATTACK_REF (got '${ref}'); no scanner was built."
+            exit 2
+          fi
+          echo "PANIC_ATTACK_REF=$ref" >> "$GITHUB_ENV"
+          tool_root="$RUNNER_TEMP/panic-toolchain"
+          # Same build as the Static Analysis Gate: exact revision, locked
+          # dependencies, and proof that the installed binary names that revision.
+          timeout 600 cargo install --git https://github.com/hyperpolymath/panic-attack \
+            --rev "$ref" --locked --features http --root "$tool_root" panic-attack
+          grep -Fq "#$ref" "$tool_root/.crates.toml"
+          "$tool_root/bin/panic-attack" --version
+          jq -cn --arg sha "$ref" \
+            --arg digest "$(sha256sum "$tool_root/bin/panic-attack" | cut -d' ' -f1)" \
+            --arg rust "$(rustc --version)" --arg cargo "$(cargo --version)" \
+            '{source_sha:$sha,binary_sha256:$digest,features:["http"],rustc:$rust,cargo:$cargo}' \
+            > "$tool_root/source.json"
+          echo "$tool_root/bin" >> "$GITHUB_PATH"
 
-      - name: Bridge triage (queries OSV) -> BridgeReport
-        run: panic-attack bridge triage . --output bridge-report.json
+      # The adapter that the Static Analysis Gate uses. It checks the binary
+      # against its build receipt and writes a receipt only for a complete
+      # schema 0.3.0 report whose vulnerability_data is "queried".
+      - name: Bridge triage (queries OSV) -> qualified BridgeReport
+        env:
+          SCAN_EXPECTED_SHA: ${{ github.sha }}
+        run: |
+          bash scripts/ci/static-analysis-evidence.sh scan patch-bridge "$PANIC_ATTACK_REF" \
+            "$RUNNER_TEMP/panic-toolchain/bin/panic-attack" "$RUNNER_TEMP/panic-toolchain/source.json" \
+            "$RUNNER_TEMP/bridge-report"
 
+      # Exit 1: a reachable unmitigable CVE. Exit 2: no qualified report, so
+      # there is no CVE result to judge. Controls for both are in
+      # scripts/ci/test-static-analysis-evidence.sh.
       - name: Apply B1 verdict -- reachable unmitigable CVE -> flag
-        run: |
-          blockers=$(jq '[.cves[]? | select(.classification=="Unmitigable" and .reachability.status=="Reachable")] | length' bridge-report.json)
-          if [ "$blockers" -gt 0 ]; then
-            echo "::error::B1: $blockers reachable unmitigable CVE(s) -> safety=flag (auto-merge blocked)"
-            jq -r '.cves[]? | select(.classification=="Unmitigable" and .reachability.status=="Reachable") | "  - \(.vulnerability.cve // .vulnerability.id): \(.rationale)"' bridge-report.json
-            exit 1
-          fi
-          echo "B1 PASS: no reachable unmitigable CVEs -> arm-eligible (pool-gated)."
+        env:
+          SCAN_EXPECTED_SHA: ${{ github.sha }}
+        run: bash scripts/ci/static-analysis-evidence.sh bridge-b1 "$RUNNER_TEMP/bridge-report/receipt.json"
diff --git a/scripts/ci/static-analysis-evidence.sh b/scripts/ci/static-analysis-evidence.sh
index 49f43fff..215ca501 100755
--- a/scripts/ci/static-analysis-evidence.sh
+++ b/scripts/ci/static-analysis-evidence.sh
@@ -246,9 +246,43 @@ deposit() {
          + [$hyp[0][] | . + {scanner:"hypatia"}]),patch_bridge:$bridge[0]}' > "$dir/unified-findings.json"
 }
 
+# Merge-orchestration B1 (bridge-gate.yml): a reachable unmitigable CVE blocks a
+# dependency bump. Exit 1 is that verdict. Exit 2 means there is no CVE result
+# to judge: the receipt is not a qualified Patch Bridge receipt (which requires
+# vulnerability_data == "queried"), or a CVE carries a reachability status this
+# gate does not know. An unknown value must never count as "not reachable".
+bridge_b1() {
+  local receipt=$1 report blockers
+  local reachable_unmitigable='.cves[] | select(.classification == "unmitigable" and .reachability.status == "reachable")'
+  one_json "$receipt" || return 2
+  report=$(mktemp)
+  if [[ "$(jq -r '.tool' "$receipt")" != patch-bridge ]] ||
+     ! qualified_receipt patch-bridge "${PANIC_ATTACK_REF:?}" "$receipt" "$report"; then
+    rm -f -- "$report"
+    echo '::error::B1: no qualified Patch Bridge report. The vulnerability feed must be queried; this is not a CVE result.' >&2
+    return 2
+  fi
+  if ! jq -e 'all(.cves[]; .reachability.status as $s |
+       ["phantom-declared","phantom-transitive","unreachable","reachable"] | index($s) != null)' "$report" >/dev/null 2>&1; then
+    rm -f -- "$report"
+    echo '::error::B1: a CVE has no known reachability status; the report does not match the pinned contract.' >&2
+    return 2
+  fi
+  blockers=$(jq "[$reachable_unmitigable] | length" "$report")
+  if [[ "$blockers" -gt 0 ]]; then
+    echo "::error::B1: $blockers reachable unmitigable CVE(s) -> safety=flag (auto-merge blocked)"
+    jq -r "$reachable_unmitigable"' | "  - \(.vulnerability.cve // .vulnerability.id // "unidentified"): \(.rationale // "no rationale")"' "$report"
+    rm -f -- "$report"
+    return 1
+  fi
+  rm -f -- "$report"
+  echo 'B1 PASS: the feed was queried and no unmitigable CVE is reachable -> arm-eligible (pool-gated).'
+}
+
 case "${1:-}" in
   scan) shift; scan "$@" ;;
   gate) shift; gate "$@" ;;
   deposit) shift; deposit "$@" ;;
-  *) echo 'usage: static-analysis-evidence.sh scan TOOL REF BIN SOURCE-RECEIPT OUTPUT-DIR | gate RECEIPT | deposit ARTIFACT-DIR' >&2; exit 2 ;;
+  bridge-b1) shift; bridge_b1 "$@" ;;
+  *) echo 'usage: static-analysis-evidence.sh scan TOOL REF BIN SOURCE-RECEIPT OUTPUT-DIR | gate RECEIPT | deposit ARTIFACT-DIR | bridge-b1 RECEIPT' >&2; exit 2 ;;
 esac
diff --git a/scripts/ci/test-static-analysis-evidence.sh b/scripts/ci/test-static-analysis-evidence.sh
index 07b5f20b..119cdfd4 100755
--- a/scripts/ci/test-static-analysis-evidence.sh
+++ b/scripts/ci/test-static-analysis-evidence.sh
@@ -162,6 +162,58 @@ expect_exit 2 bridge
 printf '%s\n' '{"schema_version":"0.2.0","total_dependencies":2,"vulnerable_dependencies":1,"cves":[{"classification":"unmitigable"}],"mitigated":0,"unmitigable":1,"concatenative":0,"informational":0}' > "$MOCK_REPORT"
 expect_exit 2 bridge
 
+# B1 (bridge-gate.yml): exit 1 only for a reachable unmitigable CVE in a
+# qualified report. No qualified report, or an unknown reachability value, is
+# exit 2: it is never a pass.
+b1() { bash "$adapter" bridge-b1 "$tmp/bridge/receipt.json"; }
+bridge_report() { # <vulnerability_data> <classification> <reachability status>
+  local data=$1 class=$2 reach=$3
+  jq -cn --arg data "$data" --arg class "$class" --arg reach "$reach" '
+    {schema_version:"0.3.0",vulnerability_data:$data,total_dependencies:2,vulnerable_dependencies:1,
+     cves:[{classification:$class,reachability:{status:$reach},vulnerability:{id:"FIXTURE-0001"},rationale:"planted"}],
+     mitigated:(if $class == "mitigable" then 1 else 0 end),unmitigable:(if $class == "unmitigable" then 1 else 0 end),
+     concatenative:0,informational:(if $class == "informational" then 1 else 0 end)}' > "$MOCK_REPORT"
+}
+bridge_report queried unmitigable reachable
+expect_exit 0 bridge
+expect_exit 1 b1
+grep -Fq 'FIXTURE-0001: planted' "$tmp/control.log"
+# Paired: the same CVE does not block when it is not reachable or is mitigable.
+for reach in unreachable phantom-declared phantom-transitive; do
+  bridge_report queried unmitigable "$reach"
+  expect_exit 0 bridge
+  expect_exit 0 b1
+done
+bridge_report queried mitigable reachable
+expect_exit 0 bridge
+expect_exit 0 b1
+printf '%s\n' '{"schema_version":"0.3.0","vulnerability_data":"queried","total_dependencies":2,"vulnerable_dependencies":0,"cves":[],"mitigated":0,"unmitigable":0,"concatenative":0,"informational":0}' > "$MOCK_REPORT"
+expect_exit 0 bridge
+expect_exit 0 b1
+# The spelling the workflow compared before #481 never matched the report.
+# An unknown status is refused, so a renamed value cannot pass in silence.
+bridge_report queried unmitigable Reachable
+expect_exit 0 bridge
+expect_exit 2 b1
+# A report whose feed was not queried leaves no qualified receipt to judge.
+for data in offline-unavailable no-dependencies; do
+  bridge_report "$data" unmitigable reachable
+  expect_exit 2 bridge
+  expect_exit 2 b1
+done
+# The verdict checks the report itself, not only that a receipt exists: a
+# receipt whose report says the feed was not queried, or says nothing about
+# the feed, is refused. Without that check this zero-CVE report would pass.
+printf '%s\n' '{"schema_version":"0.3.0","vulnerability_data":"queried","total_dependencies":2,"vulnerable_dependencies":0,"cves":[],"mitigated":0,"unmitigable":0,"concatenative":0,"informational":0}' > "$MOCK_REPORT"
+expect_exit 0 bridge
+jq '.report.vulnerability_data = "offline-unavailable"' "$tmp/bridge/receipt.json" > "$tmp/unqueried-receipt.json"
+expect_exit 2 bash "$adapter" bridge-b1 "$tmp/unqueried-receipt.json"
+jq 'del(.report.vulnerability_data)' "$tmp/bridge/receipt.json" > "$tmp/unqueried-receipt.json"
+expect_exit 2 bash "$adapter" bridge-b1 "$tmp/unqueried-receipt.json"
+# Another scanner's receipt and a missing receipt are not CVE results.
+expect_exit 2 bash "$adapter" bridge-b1 "$tmp/qualified-hypatia.json"
+expect_exit 2 bash "$adapter" bridge-b1 "$tmp/no-such-receipt.json"
+
 # Deposit preserves actual critical findings even though their gate failed.
 # Only mutually matching completed scan receipts may create the legacy artifact.
 mkdir -p "$tmp/findings/"{panic-attack-findings,hypatia-findings,bridge-report}