diff --git a/.github/workflows/security-scan.yml b/.github/workflows/security-scan.yml
index 500e22b4ab..e04d7bf8f3 100644
--- a/.github/workflows/security-scan.yml
+++ b/.github/workflows/security-scan.yml
@@ -164,7 +164,7 @@ jobs:
         with:
           scan-args: |
             --format=json
-            --output=old-results.json
+            --output-file=old-results.json
             --maven-registry=https://maven-central.storage-download.googleapis.com/maven2
             --no-resolve
             --allow-no-lockfiles
@@ -182,7 +182,7 @@ jobs:
         with:
           scan-args: |
             --format=json
-            --output=old-results.json
+            --output-file=old-results.json
             --no-resolve
             --allow-no-lockfiles
             -r
@@ -215,7 +215,7 @@ jobs:
         with:
           scan-args: |
             --format=json
-            --output=new-results.json
+            --output-file=new-results.json
             --maven-registry=https://maven-central.storage-download.googleapis.com/maven2
             --no-resolve
             --allow-no-lockfiles
@@ -233,7 +233,7 @@ jobs:
         with:
           scan-args: |
             --format=json
-            --output=new-results.json
+            --output-file=new-results.json
             --no-resolve
             --allow-no-lockfiles
             -r
@@ -286,7 +286,7 @@ jobs:
         uses: google/osv-scanner-action/osv-reporter-action@8e5cf47b818121e8b405931c82126c2630b0b20d # v2.3.8
         with:
           scan-args: |
-            --output=results.sarif
+            --output-files=results.sarif
             --old=old-results.json
             --new=new-results.json
             --gh-annotations=true
@@ -323,6 +323,10 @@ jobs:
         uses: github/codeql-action/upload-sarif@cdf488f595d80d6e07e03d4674febd5ab45fa938 # v4.37.9
         with:
           sarif_file: results.sarif
+          # The exact head checkout lives in `source`, not the workspace root;
+          # without this binding upload-sarif logs "does not appear to be a git
+          # repository" twice and falls back to server-derived commit identity.
+          checkout_path: ${{ github.workspace }}/source
           # results.sarif is produced after checkout of the pull request head.
           # Uploading it against refs/pull/*/merge can race GitHub's synthetic
           # merge ref and fail with "commit_oid is not a merge commit".
diff --git a/tests/test_required_workflow_queue_contract.py b/tests/test_required_workflow_queue_contract.py
index 19fe6b0f7f..87277d45f5 100644
--- a/tests/test_required_workflow_queue_contract.py
+++ b/tests/test_required_workflow_queue_contract.py
@@ -1674,8 +1674,8 @@ def test_security_scan_preserves_base_output_across_cross_fork_checkout() -> Non
 
     assert workflow.count("--allow-no-lockfiles") == 4
     assert workflow.count("path: source") == 2
-    assert workflow.count("--output=old-results.json") == 2
-    assert workflow.count("--output=new-results.json") == 2
+    assert workflow.count("--output-file=old-results.json") == 2
+    assert workflow.count("--output-file=new-results.json") == 2
     assert workflow.count("source/") == 4
     assert "clean: false" not in workflow
     assert "test -s old-results.json" in workflow
@@ -1732,12 +1732,47 @@ def test_osv_scan_logs_and_retries_without_transitive_resolution_on_resolver_fai
         "Retry head OSV without transitive resolution\n        if: steps.osv_head.outcome == 'failure'\n        continue-on-error: true"
         in workflow
     )
-    assert "--output=old-results.json" in workflow
-    assert "--output=new-results.json" in workflow
+    assert "--output-file=old-results.json" in workflow
+    assert "--output-file=new-results.json" in workflow
     assert "Print OSV findings being compared" in workflow
     assert "OSV {label} scan produced {len(findings)} finding(s)" in workflow
 
 
+def test_osv_scan_uses_current_output_flags_and_binds_sarif_checkout_path() -> None:
+    """Drop deprecated OSV output flags and bind upload-sarif to the real checkout.
+
+    Live evidence (ContextualWisdomLab/.github#2132): the pinned
+    `ghcr.io/google/osv-scanner-action:v2.5.1` image warns
+    `--output has been deprecated in favor of --output-file` (scanner) and
+    `... in favor of --output-files` (reporter), and `upload-sarif` logged
+    twice that the workspace root "does not appear to be a git repository"
+    because the exact head is checked out into `source`. A bare
+    `--output-files=<path>` defaults to the sarif format in v2.5.1, so the
+    reporter's output is unchanged. The checkout-path assertion is the
+    negative fixture: an absent or wrong `checkout_path` fails here instead
+    of silently relying on server-derived commit identity.
+    """
+    workflow = workflow_text("security-scan.yml")
+
+    # Check each named scanner/reporter step on its own, so a flag removed from
+    # one step cannot hide behind the same string appearing elsewhere.
+    for step_name, output_flag in (
+        ("Scan base with OSV", "--output-file=old-results.json"),
+        ("Retry base OSV without transitive resolution", "--output-file=old-results.json"),
+        ("Scan head with OSV", "--output-file=new-results.json"),
+        ("Retry head OSV without transitive resolution", "--output-file=new-results.json"),
+        ("Report PR-introduced OSV findings", "--output-files=results.sarif"),
+    ):
+        step = workflow_step(workflow, step_name)
+        assert output_flag in step, step_name
+        assert "\n            --output=" not in step, step_name
+
+    head_checkout = workflow_step(workflow, "Checkout head")
+    checkout_dir = re.search(r"(?m)^\s+path: (\S+)$", head_checkout).group(1)
+    upload_step = workflow_step(workflow, "Upload OSV SARIF to code scanning")
+    assert f"checkout_path: ${{{{ github.workspace }}}}/{checkout_dir}" in upload_step
+
+
 def test_osv_sarif_upload_is_marked_comprehensive_after_clean_comparison(
     tmp_path: Path,
 ) -> None: