diff --git a/src/signals/extension-contributor-context.ts b/src/signals/extension-contributor-context.ts
index 53e7e3a1fd..bf2995e651 100644
--- a/src/signals/extension-contributor-context.ts
+++ b/src/signals/extension-contributor-context.ts
@@ -1,4 +1,5 @@
 import type { ContributorOpportunity, PublicReadinessScore } from "./engine";
+import { PUBLIC_UNSAFE_TERMS } from "./redaction";
 
 // ─── Contributor-context payloads for the browser extension (#556) ───────────────────────────────
 // The contributor (miner) side of the extension overlay. Every payload here is PUBLIC-SAFE and self-
@@ -20,9 +21,13 @@ export function contributorReadinessBand(total: number): ContributorReadinessBan
 // Defense-in-depth public-safe redaction for any free-form text that reaches the contributor overlay.
 // The upstream builders are already contributor-facing, but every string is re-checked here and any
 // forbidden private term (reward/wallet/key material/raw trust score/etc.) is redacted rather than
-// leaked. Kept local (no import) so this module stays cycle-free and the API never 500s on a stray term.
-const FORBIDDEN_EXTENSION_TERMS =
-  /\b(?:rewards?|payouts?|farming|wallets?|hotkeys?|coldkeys?|seed[-\s]?phrases?|mnemonics?|private[-\s]?keys?|raw[-\s]?trust(?:[-\s]?scores?)?|trust[-\s]?scores?|score[-\s]?(?:estimate|preview|prediction)s?|estimated[-\s]?scores?|scoreability|private[-\s]?reviewability|reviewability[-\s]?internals?|private[-\s]?rankings?)\b/gi;
+// leaked. Composed from the canonical `PUBLIC_UNSAFE_TERMS` alternation (redaction.ts) plus a couple of
+// extension-only terms that aren't part of that shared vocabulary, so this list can't silently drift
+// from the canonical public/private boundary again (#5840). Only the plain string constant is imported
+// (not the whole redaction module), and redaction.ts has no imports of its own, so this stays cycle-free.
+const FORBIDDEN_EXTENSION_ONLY_TERMS = String.raw`seed[-\s]?phrases?|private[-\s]?keys?`;
+
+const FORBIDDEN_EXTENSION_TERMS = new RegExp(String.raw`\b(?:${PUBLIC_UNSAFE_TERMS}|${FORBIDDEN_EXTENSION_ONLY_TERMS})\b`, "gi");
 
 export function redactExtensionText(text: string): string {
   return text.replace(FORBIDDEN_EXTENSION_TERMS, "[redacted]").replace(/\s+/g, " ").trim();
diff --git a/test/unit/extension-contributor-context.test.ts b/test/unit/extension-contributor-context.test.ts
index 08b8053f27..195402f29e 100644
--- a/test/unit/extension-contributor-context.test.ts
+++ b/test/unit/extension-contributor-context.test.ts
@@ -6,9 +6,11 @@ import {
   contributorReadinessBand,
   redactExtensionText,
 } from "../../src/signals/extension-contributor-context";
+import { isPublicSafeText } from "../../src/signals/redaction";
 import type { ContributorOpportunity, PublicReadinessScore } from "../../src/signals/engine";
 
-const FORBIDDEN_PUBLIC_TERMS = /wallet|hotkey|coldkey|mnemonic|reward|payout|farming|raw trust|trust score|scoreability|reviewability internals|private ranking/i;
+const FORBIDDEN_PUBLIC_TERMS =
+  /wallet|hotkey|coldkey|mnemonic|reward|payout|farming|raw trust|trust score|scoreability|reviewability|cohort|ranking|miner-originated|human-originated/i;
 
 function opportunity(over: Partial<ContributorOpportunity> = {}): ContributorOpportunity {
   return {
@@ -59,6 +61,52 @@ describe("redactExtensionText", () => {
   it("leaves safe text untouched", () => {
     expect(redactExtensionText("Maintainer-created issue, good fit.")).toBe("Maintainer-created issue, good fit.");
   });
+
+  it("redacts a bare cohort reference (#5840)", () => {
+    expect(redactExtensionText("Cohort diagnostics flagged this PR")).toBe("[redacted] diagnostics flagged this PR");
+  });
+
+  it("redacts a bare ranking reference (#5840)", () => {
+    expect(redactExtensionText("Your ranking dropped this week")).toBe("Your [redacted] dropped this week");
+  });
+
+  it("redacts miner-originated and human-originated (#5840)", () => {
+    expect(redactExtensionText("This looks miner-originated, not human-originated")).toBe(
+      "This looks [redacted], not [redacted]",
+    );
+  });
+
+  it("redacts a standalone reviewability reference, not just the compound phrases (#5840)", () => {
+    expect(redactExtensionText("Reviewability is limited right now")).toBe("[redacted] is limited right now");
+  });
+});
+
+describe("FORBIDDEN_EXTENSION_TERMS drift guard (#5840)", () => {
+  it("redacts a representative sample of every canonical PUBLIC_UNSAFE_TERMS entry, so this module can't silently drift from the shared public/private boundary again", () => {
+    const samples = [
+      "Your reward is pending.",
+      "Your score is pending.",
+      "Check your wallet balance.",
+      "Rotate your hotkey.",
+      "Rotate your coldkey.",
+      "Keep the mnemonic safe.",
+      "The payout is scheduled.",
+      "Your ranking dropped this week.",
+      "Cohort diagnostics flagged this PR.",
+      "This looks miner-originated, not human-originated.",
+      "We detected farming behavior.",
+      "This uses raw trust internally.",
+      "The trust score moved.",
+      "This is private reviewability data.",
+      "Reviewability is limited right now.",
+    ];
+
+    for (const sample of samples) {
+      // Sanity check: confirm the sample really is flagged unsafe by the canonical pattern.
+      expect(isPublicSafeText(sample)).toBe(false);
+      expect(isPublicSafeText(redactExtensionText(sample))).toBe(true);
+    }
+  });
 });
 
 describe("buildExtensionIssueFit", () => {