diff --git a/CHANGELOG.md b/CHANGELOG.md
index bf192f6a9e..c5a98a7e65 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+### Change-request autofix fails closed on unknown merge state
+
+- The shared change-request gate now requires `mergeStateStatus` to be exactly `CLEAN` or `HAS_HOOKS`. Missing, empty, and unknown REST fallback values cannot authorize autofix or RCA dispatch. Proposed in ContextualWisdomLab/.github#1492.
+
 ### Failed-check finding names the Strix sandbox instead of the gateway
 
 - `opencode-review-dispatch.yml`'s `emit_strix_provider_failure_finding` rendered one fixed finding for every `STRIX_PROVIDER_UNAVAILABLE` line, whose Root cause read "The contextual-orchestrator gateway or its discovered provider pool was unavailable for this run". `#1953` had just given the Strix sandbox bootstrap failure its own second verdict token (`STRIX_SANDBOX_UNAVAILABLE`) precisely because that attribution is wrong for it -- the sandbox container never reaches its Caido proxy, so the run dies before the gateway serves anything -- and this consumer re-applied the wrong attribution one step downstream, into the review findings and the failure census. The emitter now branches on the second token: a sandbox verdict gets a finding that names Strix's sandbox, says the verdict does not name the gateway, and tells the reader not to change gateway or provider configuration on its strength. A `STRIX_PROVIDER_UNAVAILABLE` line without the token keeps its existing text verbatim, so the gateway class has no regression surface. No test covered this finding text at all before (`gateway or its discovered provider pool` matched nothing under `tests/`); `tests/test_opencode_dispatch_strix_sandbox_finding.py` now runs the production emitter from the published run block and pins both directions plus the no-signal case. Refs #1953, #1935.
diff --git a/docs/doctoring/unknown-merge-state-fail-closed.md b/docs/doctoring/unknown-merge-state-fail-closed.md
new file mode 100644
index 0000000000..6f748a5ef4
--- /dev/null
+++ b/docs/doctoring/unknown-merge-state-fail-closed.md
@@ -0,0 +1,33 @@
+# Unknown merge state does not authorize change-request automation
+
+검토 기준일: **2026-09-07**
+
+## Problem
+
+GitHub can temporarily report an unresolved mergeability state after a push.
+The REST fallback normalizes that condition to an empty value. Treating the
+empty value as clean allows automatic change-request handling without positive
+mergeability evidence.
+
+## Decision
+
+The shared gate accepts only `CLEAN` and `HAS_HOOKS`. Missing, empty, or
+unknown values return no clean review body, so neither autofix nor RCA dispatch
+is authorized. Known dirty states retain the same behavior.
+
+## Verification contract
+
+`test_change_request_gates_fail_closed_on_unknown_merge_state` covers empty,
+unknown, and absent values across the normalized body, autofix, and RCA entry
+points. Hosted exact-head checks remain mandatory.
+
+## Status
+
+**Proposed** in ContextualWisdomLab/.github#1492. Protected `main` remains the
+release authority.
+
+## Reference
+
+GitHub. (n.d.). *REST API endpoints for pull requests*. GitHub Docs. Retrieved
+September 7, 2026, from
+https://docs.github.com/en/rest/pulls/pulls
diff --git a/docs/product-technical-gap-baseline.md b/docs/product-technical-gap-baseline.md
index 1cc9e20313..f181347f5a 100644
--- a/docs/product-technical-gap-baseline.md
+++ b/docs/product-technical-gap-baseline.md
@@ -7,6 +7,12 @@
 
 이 문서는 제품·기술·운영 Gap을 현재 문서와 현재 GitHub 상태에 묶어 두는 기준선이다. 새 작업은 먼저 이 문서의 Gap ID를 PR 설명과 테스트 증거에 연결하고, PR의 정확한 exact HEAD·Checks·리뷰를 다시 수집한 뒤 구현한다. 표의 상태는 작성 시점의 관측값이므로, 병합 판단에는 재사용하지 않는다. 이 인벤토리는 스냅샷이며 merge authorization이 아니다.
 
+### 2026-09-07 unknown merge-state fail-closed amendment
+
+- **Gap:** an empty or absent REST fallback `mergeStateStatus` can pass the change-request gate as if mergeability were proven.
+- **Action:** ContextualWisdomLab/.github#1492 requires `CLEAN` or `HAS_HOOKS` explicitly before autofix or RCA classification.
+- **Status:** Proposed; exact-head hosted Checks, independent review, ordinary protected integration, and post-merge current-main verification remain required.
+
 ## 1. 근거와 범위
 
 ### 1.1 우선순위가 높은 근거
diff --git a/scripts/ci/pr_review_fix_scheduler.py b/scripts/ci/pr_review_fix_scheduler.py
old mode 100755
new mode 100644
index bc2868c5a4..66c0109e05
--- a/scripts/ci/pr_review_fix_scheduler.py
+++ b/scripts/ci/pr_review_fix_scheduler.py
@@ -203,7 +203,7 @@ def latest_current_head_opencode_review(pr: dict[str, Any]) -> dict[str, Any] |
 def _clean_change_request_body(pr: dict[str, Any]) -> str | None:
     """Return normalized exact-head OpenCode review text for a clean PR."""
     merge_state = str(pr.get("mergeStateStatus") or "").upper()
-    if merge_state and merge_state not in {"CLEAN", "HAS_HOOKS"}:
+    if merge_state not in {"CLEAN", "HAS_HOOKS"}:
         return None
     review = latest_current_head_opencode_review(pr)
     if review is None:
diff --git a/tests/test_pr_review_fix_scheduler.py b/tests/test_pr_review_fix_scheduler.py
index 6b9bd91e0c..bd5a75ea7d 100644
--- a/tests/test_pr_review_fix_scheduler.py
+++ b/tests/test_pr_review_fix_scheduler.py
@@ -483,6 +483,37 @@ def test_change_request_requires_current_head_opencode_review():
     assert not fix.change_request_is_autofixable(stale_review_pr)
 
 
+def test_change_request_gates_fail_closed_on_unknown_merge_state():
+    """Unknown or missing merge state cannot authorize automatic repair."""
+    head = "a" * 40
+    body = "Actionable source-backed finding with suggested diff."
+    current_review = {
+        "state": "CHANGES_REQUESTED",
+        "author": {"login": "opencode-agent"},
+        "commit": {"oid": head},
+        "body": body,
+    }
+
+    for merge_state in ("", "UNKNOWN"):
+        pull_request = make_pr(
+            headRefOid=head,
+            mergeStateStatus=merge_state,
+            reviews={"nodes": [current_review]},
+        )
+        assert fix._clean_change_request_body(pull_request) is None
+        assert not fix.change_request_is_autofixable(pull_request)
+        assert not fix.change_request_requires_rca(pull_request)
+
+    pull_request = make_pr(
+        headRefOid=head,
+        reviews={"nodes": [current_review]},
+    )
+    del pull_request["mergeStateStatus"]
+    assert fix._clean_change_request_body(pull_request) is None
+    assert not fix.change_request_is_autofixable(pull_request)
+    assert not fix.change_request_requires_rca(pull_request)
+
+
 def test_process_queue_dispatches_same_repo_current_head(monkeypatch, capsys):
     """The queue path dispatches one same-repository autofix."""
     pr = make_pr()