diff --git a/.gitea/workflows/gate-check-v3-tests.yml b/.gitea/workflows/gate-check-v3-tests.yml
new file mode 100644
index 000000000..bf0304dec
--- /dev/null
+++ b/.gitea/workflows/gate-check-v3-tests.yml
@@ -0,0 +1,40 @@
+name: gate-check-v3-tests
+
+# Regression unit tests for tools/gate-check-v3/gate_check.py.
+# This workflow closes the CI gap identified in molecule-core#2615:
+# the gate-check evaluator is load-bearing for merge decisions and must
+# have automated coverage for its security-sensitive governance-context
+# logic (molecule-core#2589).
+
+on:
+  push:
+    branches: [main, staging]
+    paths:
+      - 'tools/gate-check-v3/**'
+      - '.gitea/workflows/gate-check-v3-tests.yml'
+  pull_request:
+    branches: [main, staging]
+    paths:
+      - 'tools/gate-check-v3/**'
+      - '.gitea/workflows/gate-check-v3-tests.yml'
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  # bp-exempt: test-only regression suite for the gate-check evaluator.
+  # Merge blocking is enforced by the existing CI / all-required aggregate.
+  unit-tests:
+    name: gate-check-v3 unit tests
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Install pytest
+        run: pip install pytest -q
+
+      - name: Run gate-check-v3 unit tests
+        working-directory: tools/gate-check-v3
+        run: python3 -m pytest test_gate_check.py -v
diff --git a/tools/gate-check-v3/gate_check.py b/tools/gate-check-v3/gate_check.py
index 4e6b03d64..417b2c253 100644
--- a/tools/gate-check-v3/gate_check.py
+++ b/tools/gate-check-v3/gate_check.py
@@ -467,11 +467,19 @@ def signal_6_ci(pr_number: int, repo: str, branch: str | None = None, pr_data: d
     # Gitea Actions uses "status" (pending/success/failure) not "state" for
     # individual check entries. "state" is null for pending runs.
     # Exclude our own prior status to prevent self-referential failure loops.
-    check_statuses = {}
+    # Gitea /commits/<sha>/statuses is non-monotonic by id, so collapse by
+    # max(id) to guarantee the latest result for each context wins.
+    latest_by_context: dict[str, dict] = {}
     for s in combined.get("statuses") or []:
         ctx = s["context"]
-        if "gate-check" not in ctx.lower():
-            check_statuses[ctx] = s.get("status", "pending")
+        if "gate-check" in ctx.lower():
+            continue
+        existing = latest_by_context.get(ctx)
+        if existing is None or s.get("id", 0) > existing.get("id", 0):
+            latest_by_context[ctx] = s
+    check_statuses = {
+        ctx: s.get("status", "pending") for ctx, s in latest_by_context.items()
+    }
 
     # Try to get branch protection for required checks
     required_checks = []
diff --git a/tools/gate-check-v3/test_gate_check.py b/tools/gate-check-v3/test_gate_check.py
index bf9a1396c..ef2516bdd 100644
--- a/tools/gate-check-v3/test_gate_check.py
+++ b/tools/gate-check-v3/test_gate_check.py
@@ -379,16 +379,19 @@ def test_signal_6_missing_required_context_returns_ci_pending(monkeypatch):
     monkeypatch.setattr(
         mod, "api_get",
         _signal_6_api_get(
-            required_checks=["qa-review / approved (pull_request)", "security-review / approved (pull_request)"],
+            required_checks=[
+                "qa-review / approved (pull_request_target)",
+                "security-review / approved (pull_request_target)",
+            ],
             statuses=[
-                {"context": "qa-review / approved (pull_request)", "status": "success"},
+                {"context": "qa-review / approved (pull_request_target)", "status": "success"},
                 # security-review is completely missing
             ],
         ),
     )
     result = mod.signal_6_ci(200, "molecule-ai/molecule-core")
     assert result["verdict"] == "CI_PENDING"
-    assert "security-review / approved (pull_request)" in result["pending_required"]
+    assert "security-review / approved (pull_request_target)" in result["pending_required"]
 
 
 def test_signal_6_pending_required_context_returns_ci_pending(monkeypatch):
@@ -398,20 +401,20 @@ def test_signal_6_pending_required_context_returns_ci_pending(monkeypatch):
         mod, "api_get",
         _signal_6_api_get(
             required_checks=[
-                "qa-review / approved (pull_request)",
-                "security-review / approved (pull_request)",
-                "sop-checklist / all-items-acked (pull_request)",
+                "qa-review / approved (pull_request_target)",
+                "security-review / approved (pull_request_target)",
+                "sop-checklist / all-items-acked (pull_request_target)",
             ],
             statuses=[
-                {"context": "qa-review / approved (pull_request)", "status": "success"},
-                {"context": "security-review / approved (pull_request)", "status": "pending"},
-                {"context": "sop-checklist / all-items-acked (pull_request)", "status": "success"},
+                {"context": "qa-review / approved (pull_request_target)", "status": "success"},
+                {"context": "security-review / approved (pull_request_target)", "status": "pending"},
+                {"context": "sop-checklist / all-items-acked (pull_request_target)", "status": "success"},
             ],
         ),
     )
     result = mod.signal_6_ci(200, "molecule-ai/molecule-core")
     assert result["verdict"] == "CI_PENDING"
-    assert "security-review / approved (pull_request)" in result["pending_required"]
+    assert "security-review / approved (pull_request_target)" in result["pending_required"]
 
 
 def test_signal_6_failing_required_context_returns_ci_fail(monkeypatch):
@@ -421,22 +424,22 @@ def test_signal_6_failing_required_context_returns_ci_fail(monkeypatch):
         mod, "api_get",
         _signal_6_api_get(
             required_checks=[
-                "qa-review / approved (pull_request)",
-                "security-review / approved (pull_request)",
-                "sop-checklist / all-items-acked (pull_request)",
+                "qa-review / approved (pull_request_target)",
+                "security-review / approved (pull_request_target)",
+                "sop-checklist / all-items-acked (pull_request_target)",
                 "CI / all-required (pull_request)",
             ],
             statuses=[
-                {"context": "qa-review / approved (pull_request)", "status": "failure"},
-                {"context": "security-review / approved (pull_request)", "status": "success"},
-                {"context": "sop-checklist / all-items-acked (pull_request)", "status": "success"},
+                {"context": "qa-review / approved (pull_request_target)", "status": "failure"},
+                {"context": "security-review / approved (pull_request_target)", "status": "success"},
+                {"context": "sop-checklist / all-items-acked (pull_request_target)", "status": "success"},
                 {"context": "CI / all-required (pull_request)", "status": "success"},
             ],
         ),
     )
     result = mod.signal_6_ci(200, "molecule-ai/molecule-core")
     assert result["verdict"] == "CI_FAIL"
-    assert "qa-review / approved (pull_request)" in result["failing_required"]
+    assert "qa-review / approved (pull_request_target)" in result["failing_required"]
 
 
 def test_signal_6_all_required_green_returns_clear(monkeypatch):
@@ -446,15 +449,15 @@ def test_signal_6_all_required_green_returns_clear(monkeypatch):
         mod, "api_get",
         _signal_6_api_get(
             required_checks=[
-                "qa-review / approved (pull_request)",
-                "security-review / approved (pull_request)",
-                "sop-checklist / all-items-acked (pull_request)",
+                "qa-review / approved (pull_request_target)",
+                "security-review / approved (pull_request_target)",
+                "sop-checklist / all-items-acked (pull_request_target)",
                 "CI / all-required (pull_request)",
             ],
             statuses=[
-                {"context": "qa-review / approved (pull_request)", "status": "success"},
-                {"context": "security-review / approved (pull_request)", "status": "success"},
-                {"context": "sop-checklist / all-items-acked (pull_request)", "status": "success"},
+                {"context": "qa-review / approved (pull_request_target)", "status": "success"},
+                {"context": "security-review / approved (pull_request_target)", "status": "success"},
+                {"context": "sop-checklist / all-items-acked (pull_request_target)", "status": "success"},
                 {"context": "CI / all-required (pull_request)", "status": "success"},
             ],
         ),
@@ -481,6 +484,85 @@ def test_signal_6_governance_checks_always_required_even_when_bp_empty(monkeypat
     )
     result = mod.signal_6_ci(200, "molecule-ai/molecule-core")
     assert result["verdict"] == "CI_PENDING"
-    assert "qa-review / approved (pull_request)" in result["pending_required"]
-    assert "security-review / approved (pull_request)" in result["pending_required"]
-    assert "sop-checklist / all-items-acked (pull_request)" in result["pending_required"]
+    assert "qa-review / approved (pull_request_target)" in result["pending_required"]
+    assert "security-review / approved (pull_request_target)" in result["pending_required"]
+    assert "sop-checklist / all-items-acked (pull_request_target)" in result["pending_required"]
+
+
+# ── Signal 6 regression tests for molecule-core#2589 ─────────────────────────
+
+TRUSTED_QA = "qa-review / approved (pull_request_target)"
+TRUSTED_SECURITY = "security-review / approved (pull_request_target)"
+TRUSTED_SOP = "sop-checklist / all-items-acked (pull_request_target)"
+UNTRUSTED_QA = "qa-review / approved (pull_request)"
+UNTRUSTED_SECURITY = "security-review / approved (pull_request)"
+UNTRUSTED_SOP = "sop-checklist / all-items-acked (pull_request)"
+
+
+def test_signal_6_trusted_governance_contexts_clear(monkeypatch):
+    """#2589 regression: gate is satisfied ONLY by trusted (pull_request_target)
+    governance contexts."""
+    mod = load_gate_check()
+    monkeypatch.setattr(
+        mod, "api_get",
+        _signal_6_api_get(
+            required_checks=[],
+            statuses=[
+                {"context": TRUSTED_QA, "status": "success"},
+                {"context": TRUSTED_SECURITY, "status": "success"},
+                {"context": TRUSTED_SOP, "status": "success"},
+            ],
+        ),
+    )
+    result = mod.signal_6_ci(200, "molecule-ai/molecule-core")
+    assert result["verdict"] == "CLEAR"
+    assert result["passing_required"] == [TRUSTED_QA, TRUSTED_SECURITY, TRUSTED_SOP]
+
+
+def test_signal_6_untrusted_governance_contexts_do_not_satisfy(monkeypatch):
+    """#2589 security regression: forged/untrusted (pull_request)-suffixed
+    governance statuses must NOT satisfy the gate."""
+    mod = load_gate_check()
+    monkeypatch.setattr(
+        mod, "api_get",
+        _signal_6_api_get(
+            required_checks=[],
+            statuses=[
+                # Attacker-controlled PR-head workflow posts the untrusted suffixes.
+                {"context": UNTRUSTED_QA, "status": "success"},
+                {"context": UNTRUSTED_SECURITY, "status": "success"},
+                {"context": UNTRUSTED_SOP, "status": "success"},
+            ],
+        ),
+    )
+    result = mod.signal_6_ci(200, "molecule-ai/molecule-core")
+    assert result["verdict"] in ("CI_PENDING", "CI_FAIL")
+    # Trusted contexts are still missing/unsatisfied.
+    for ctx in (TRUSTED_QA, TRUSTED_SECURITY, TRUSTED_SOP):
+        assert ctx in result["pending_required"]
+    # Untrusted contexts are NOT counted as passing governance.
+    for ctx in (UNTRUSTED_QA, UNTRUSTED_SECURITY, UNTRUSTED_SOP):
+        assert ctx not in result["passing_required"]
+
+
+def test_signal_6_status_collapse_uses_max_id(monkeypatch):
+    """Gitea /commits/<sha>/statuses is non-monotonic by id; the gate must
+    collapse duplicate contexts by max(id), not by list order."""
+    mod = load_gate_check()
+    monkeypatch.setattr(
+        mod, "api_get",
+        _signal_6_api_get(
+            required_checks=[TRUSTED_QA],
+            statuses=[
+                # Older id claims success; newer id claims failure.
+                # List order is deliberately opposite of id order.
+                {"id": 3, "context": TRUSTED_QA, "status": "failure"},
+                {"id": 1, "context": TRUSTED_QA, "status": "success"},
+                {"id": 2, "context": TRUSTED_QA, "status": "success"},
+            ],
+        ),
+    )
+    result = mod.signal_6_ci(200, "molecule-ai/molecule-core")
+    assert result["verdict"] == "CI_FAIL"
+    assert TRUSTED_QA in result["failing_required"]
+    assert result["all_check_statuses"][TRUSTED_QA] == "failure"