diff --git a/ops/tag-v1.sh b/ops/tag-v1.sh
index 2724e83..c6b89b6 100755
--- a/ops/tag-v1.sh
+++ b/ops/tag-v1.sh
@@ -3,9 +3,17 @@
 # Creates v1.0.0 annotated tag and moving v1 tag on Quantum-L9/l9-ci-core.
 # PREREQUISITE: Run from inside the l9-ci-core repo root with a clean working tree.
 # PREREQUISITE: git remote 'origin' must point to Quantum-L9/l9-ci-core.
+# PREREQUISITE: Run ops/verify-v1-anchor.sh first to re-confirm zero floating
+#               third-party Action refs at EXPECTED_SHA before tagging.
 set -euo pipefail
 
-EXPECTED_SHA="2b330a5aab90cd7781bef08f14c5e7904b61bc56"
+# Anchor: last commit of the pre-v2-rewrite v1 lineage (direct parent of the
+# v2 rewrite commit 54a2f2fc8d060674d544fab14388bb5eff6b8e78 on l9-ci-core).
+# Supersedes the originally-planned 2b330a5aab90cd7781bef08f14c5e7904b61bc56,
+# which predated the Actions SHA-pinning hardening fix (PR #8 / 8928005) and
+# would have frozen floating actions/checkout@v6, ossf/scorecard-action@v2,
+# github/codeql-action/upload-sarif@v4 refs into an "immutable" tag.
+EXPECTED_SHA="2a3270be5f5184099c33a101807f65b1becf4e7c"
 REPO="Quantum-L9/l9-ci-core"
 
 echo "=== Quantum-L9 l9-ci-core @v1 Tag Creation Script ==="
@@ -52,7 +60,7 @@ git checkout "$EXPECTED_SHA"
 if git rev-parse "v1.0.0" >/dev/null 2>&1; then
   echo "⚠️  Tag v1.0.0 already exists. Skipping creation."
 else
-  git tag -a v1.0.0 -m "v1.0.0 — initial kernel release: 8 workflow_call kernels (pr-pipeline, release-publish, nightly, pre-commit-ci, trio-governance, security, scorecard, sbom)"
+  git tag -a v1.0.0 -m "v1.0.0 — initial kernel release: 8 workflow_call kernels (pr-pipeline, release-publish, nightly, pre-commit-ci, trio-governance, security, scorecard, sbom); all static third-party actions SHA-pinned"
   echo "✅ Annotated tag v1.0.0 created."
 fi
 
diff --git a/ops/verify-v1-anchor.sh b/ops/verify-v1-anchor.sh
new file mode 100755
index 0000000..8c4d631
--- /dev/null
+++ b/ops/verify-v1-anchor.sh
@@ -0,0 +1,175 @@
+#!/usr/bin/env bash
+# ops/verify-v1-anchor.sh
+#
+# Lightweight, read-only pre-tag check: re-confirms zero floating (non-SHA)
+# third-party GitHub Action references in the workflow_call kernels at the
+# EXPECTED_SHA anchor that ops/tag-v1.sh is about to freeze as v1.0.0 / v1
+# on Quantum-L9/l9-ci-core.
+#
+# Run this BEFORE ops/tag-v1.sh, every time, even if EXPECTED_SHA "hasn't
+# changed" — it costs seconds and is the only thing standing between an
+# "immutable" tag and permanently frozen floating-tag supply-chain risk.
+#
+# This script does not tag, push, or mutate any repository. It only fetches
+# the single anchor commit (read-only) from Quantum-L9/l9-ci-core into a
+# throwaway temp directory and inspects file contents at that commit.
+#
+# Scope: only the workflow_call kernels (the reusable workflows consumers
+# actually import via @v1 / @v1.0.0) are checked. l9-self-ci.yml is
+# deliberately excluded — it is a self-triggering, repo-internal gate with
+# no workflow_call trigger, so it is never exposed to downstream consumers
+# and its (pre-existing, unrelated) floating refs do not carry consumer
+# supply-chain risk. See AGENTS.md-equivalent note in tag-v1.sh.
+#
+# Usage: ops/verify-v1-anchor.sh
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+TAG_SCRIPT="$SCRIPT_DIR/tag-v1.sh"
+SOURCE_REPO="https://github.com/Quantum-L9/l9-ci-core.git"
+
+echo "=== v1 anchor verification (read-only) ==="
+echo ""
+
+# 1. Read EXPECTED_SHA out of tag-v1.sh so the two scripts can never drift
+#    into disagreement about which commit is being tagged.
+if [[ ! -f "$TAG_SCRIPT" ]]; then
+  echo "❌ ERROR: $TAG_SCRIPT not found (run this script from the ops/ dir, or keep both scripts together)."
+  exit 1
+fi
+
+EXPECTED_SHA=$(grep -m1 '^EXPECTED_SHA=' "$TAG_SCRIPT" | sed -E 's/^EXPECTED_SHA="([0-9a-f]{40})"$/\1/')
+if [[ ! "$EXPECTED_SHA" =~ ^[0-9a-f]{40}$ ]]; then
+  echo "❌ ERROR: Could not parse a 40-char EXPECTED_SHA out of $TAG_SCRIPT"
+  exit 1
+fi
+
+echo "Anchor SHA (parsed from ops/tag-v1.sh): $EXPECTED_SHA"
+echo ""
+
+# 2. Fetch just that commit from l9-ci-core into a scratch work dir.
+WORK_DIR="$(mktemp -d)"
+trap 'rm -rf "$WORK_DIR"' EXIT
+
+git -C "$WORK_DIR" init -q
+echo "Fetching $EXPECTED_SHA from $SOURCE_REPO..."
+if ! git -C "$WORK_DIR" fetch -q "$SOURCE_REPO" "$EXPECTED_SHA" 2>/dev/null; then
+  echo "❌ ERROR: Could not fetch $EXPECTED_SHA from $SOURCE_REPO."
+  echo "   Confirm the SHA exists and is reachable from some branch/tag on that repo."
+  exit 1
+fi
+
+RESOLVED_SHA=$(git -C "$WORK_DIR" rev-parse FETCH_HEAD)
+if [[ "$RESOLVED_SHA" != "$EXPECTED_SHA" ]]; then
+  echo "❌ ERROR: Fetched commit ($RESOLVED_SHA) does not match EXPECTED_SHA ($EXPECTED_SHA)."
+  exit 1
+fi
+echo "✅ Fetched commit matches EXPECTED_SHA exactly."
+echo ""
+
+# 3. Enumerate workflow_call kernels at this SHA (auto-detected by trigger,
+#    not a hardcoded filename list, so this self-adapts if kernels are
+#    renamed/added/removed later).
+ALL_WORKFLOW_FILES=()
+while IFS= read -r f; do
+  ALL_WORKFLOW_FILES+=("$f")
+done < <(git -C "$WORK_DIR" ls-tree -r FETCH_HEAD --name-only -- .github/workflows 2>/dev/null | sort)
+if [[ "${#ALL_WORKFLOW_FILES[@]}" -eq 0 ]]; then
+  echo "❌ ERROR: No .github/workflows/*.yml files found at $EXPECTED_SHA."
+  exit 1
+fi
+
+KERNEL_FILES=()
+for f in "${ALL_WORKFLOW_FILES[@]}"; do
+  if git -C "$WORK_DIR" show "FETCH_HEAD:$f" | grep -q '^\s*workflow_call:'; then
+    KERNEL_FILES+=("$f")
+  fi
+done
+
+if [[ "${#KERNEL_FILES[@]}" -eq 0 ]]; then
+  echo "❌ ERROR: No workflow_call kernels found at $EXPECTED_SHA — anchor looks wrong."
+  exit 1
+fi
+
+echo "Total workflow files at anchor:      ${#ALL_WORKFLOW_FILES[@]}"
+echo "workflow_call kernels (in scope):    ${#KERNEL_FILES[@]}"
+printf '  - %s\n' "${KERNEL_FILES[@]}"
+echo "Excluded (no workflow_call trigger — not consumer-facing):"
+for f in "${ALL_WORKFLOW_FILES[@]}"; do
+  skip=false
+  for k in "${KERNEL_FILES[@]}"; do
+    [[ "$f" == "$k" ]] && skip=true && break
+  done
+  [[ "$skip" == false ]] && echo "  - $f"
+done
+echo ""
+
+# 4. Documented exceptions: dynamic (non-static) uses: refs that cannot be
+#    SHA-pinned because the action path itself is computed at runtime, not
+#    a floating-tag oversight. Each entry MUST carry a one-line
+#    justification. Do NOT add entries here to silence a real finding —
+#    only for genuinely dynamic/computed uses: paths.
+ALLOWLIST_FILES=("pr-pipeline.yml")
+ALLOWLIST_PATTERNS=('^oxsecurity/megalinter/flavors/\$\{\{[^}]*\}\}@v8$')
+ALLOWLIST_REASONS=("MegaLinter flavor is resolved from a prior step's output (steps.flavor.outputs.flavor); the action path is computed at runtime and cannot be a static SHA pin. Advisory job only (DISABLE_ERRORS: true), does not gate merges.")
+
+violations=()
+exceptions=0
+total_refs=0
+
+for f in "${KERNEL_FILES[@]}"; do
+  base="$(basename "$f")"
+  while IFS= read -r line_no_and_text; do
+    line_no="${line_no_and_text%%:*}"
+    line_text="${line_no_and_text#*:}"
+
+    # Extract the uses: value: strip leading list marker, key, quotes, comments.
+    uses_value=$(printf '%s' "$line_text" | sed -E 's/^[[:space:]]*-?[[:space:]]*uses:[[:space:]]*//; s/^"//; s/"[[:space:]]*$//; s/#.*$//' | xargs)
+    [[ -z "$uses_value" ]] && continue
+
+    # Skip local composite actions / docker refs — not third-party supply chain.
+    case "$uses_value" in
+      ./*|docker://*) continue ;;
+    esac
+
+    total_refs=$((total_refs + 1))
+    ref="${uses_value##*@}"
+
+    if [[ "$ref" =~ ^[0-9a-f]{40}$ ]]; then
+      continue  # properly SHA-pinned
+    fi
+
+    matched_exception=false
+    for i in "${!ALLOWLIST_PATTERNS[@]}"; do
+      if [[ "$base" == "${ALLOWLIST_FILES[$i]}" && "$uses_value" =~ ${ALLOWLIST_PATTERNS[$i]} ]]; then
+        echo "⚠️  DOCUMENTED EXCEPTION  $f:$line_no  $uses_value"
+        echo "     Reason: ${ALLOWLIST_REASONS[$i]}"
+        exceptions=$((exceptions + 1))
+        matched_exception=true
+        break
+      fi
+    done
+    [[ "$matched_exception" == true ]] && continue
+
+    violations+=("$f:$line_no  $uses_value")
+  done < <(git -C "$WORK_DIR" show "FETCH_HEAD:$f" | grep -nE '^[[:space:]]*-?[[:space:]]*uses:[[:space:]]*[A-Za-z0-9./]')
+done
+
+echo ""
+echo "=== Result ==="
+echo "Third-party 'uses:' refs inspected (kernels only): $total_refs"
+echo "Documented exceptions:                             $exceptions"
+echo "Floating (unpinned) violations:                    ${#violations[@]}"
+echo ""
+
+if [[ "${#violations[@]}" -gt 0 ]]; then
+  echo "❌ FAIL — floating third-party Action refs found in workflow_call kernels at $EXPECTED_SHA:"
+  printf '   %s\n' "${violations[@]}"
+  echo ""
+  echo "Do NOT run ops/tag-v1.sh against this SHA. Fix EXPECTED_SHA or the anchor commit first."
+  exit 1
+fi
+
+echo "✅ PASS — $EXPECTED_SHA has zero unpinned third-party Action refs in its workflow_call kernels"
+echo "   ($exceptions documented exception(s) allow-listed above)."
+echo "It is now safe to run ops/tag-v1.sh."