diff --git a/extension/src/service-worker/__tests__/org-session.test.ts b/extension/src/service-worker/__tests__/org-session.test.ts
index 277f2a8..b1d8efe 100644
--- a/extension/src/service-worker/__tests__/org-session.test.ts
+++ b/extension/src/service-worker/__tests__/org-session.test.ts
@@ -1,17 +1,50 @@
-import { describe, expect, it, vi } from 'vitest';
+import { describe, expect, it, vi, beforeEach } from 'vitest';
 import type { SessionHandle } from '../../../wasm/relicario_wasm';
 import * as session from '../session';
 
 describe('multi-context session', () => {
-  it('clearAll frees personal and every org handle', () => {
-    const free = vi.fn();
-    const mk = (id: number) => ({ value: id, free } as unknown as SessionHandle);
-    session.setPersonal(mk(1));
-    session.setOrg('org-a', mk(2));
-    session.setOrg('org-b', mk(3));
+  beforeEach(() => {
+    // Reset module-scope state between tests via the security-zero path.
     session.clearAll();
-    expect(free).toHaveBeenCalledTimes(3);
+  });
+
+  it('clearAll frees personal and every org handle (independent mocks)', () => {
+    const fp = vi.fn(), fa = vi.fn(), fb = vi.fn();
+    session.setPersonal({ value: 1, free: fp } as unknown as SessionHandle);
+    session.setOrg('org-a', { value: 2, free: fa } as unknown as SessionHandle);
+    session.setOrg('org-b', { value: 3, free: fb } as unknown as SessionHandle);
+    session.clearAll();
+    expect(fp).toHaveBeenCalledTimes(1);
+    expect(fa).toHaveBeenCalledTimes(1);
+    expect(fb).toHaveBeenCalledTimes(1);
     expect(session.getPersonal()).toBeNull();
     expect(session.getOrg('org-a')).toBeNull();
+    expect(session.getOrg('org-b')).toBeNull();
+    expect(session.currentContext()).toBe('personal');
+  });
+
+  it('clearAll is best-effort: a throwing personal.free() still frees every org handle', () => {
+    const fp = vi.fn(() => { throw new Error('boom'); });
+    const fa = vi.fn(), fb = vi.fn();
+    session.setPersonal({ value: 1, free: fp } as unknown as SessionHandle);
+    session.setOrg('org-a', { value: 2, free: fa } as unknown as SessionHandle);
+    session.setOrg('org-b', { value: 3, free: fb } as unknown as SessionHandle);
+    expect(() => session.clearAll()).not.toThrow();
+    expect(fa).toHaveBeenCalledTimes(1);
+    expect(fb).toHaveBeenCalledTimes(1);
+    expect(session.getPersonal()).toBeNull();
+    expect(session.getOrg('org-a')).toBeNull();
+    expect(session.getOrg('org-b')).toBeNull();
+  });
+
+  it('setOrg frees the displaced handle when an org is re-unlocked', () => {
+    // Re-unlocking an org must zero the prior handle's WASM key, not orphan it.
+    const first = vi.fn(), second = vi.fn();
+    session.setOrg('org-a', { value: 1, free: first } as unknown as SessionHandle);
+    session.setOrg('org-a', { value: 2, free: second } as unknown as SessionHandle);
+    expect(first).toHaveBeenCalledTimes(1);
+    expect(second).not.toHaveBeenCalled();
+    // The new handle is the one that stays live.
+    expect((session.getOrg('org-a') as unknown as { value: number }).value).toBe(2);
   });
 });
diff --git a/extension/src/service-worker/__tests__/session.test.ts b/extension/src/service-worker/__tests__/session.test.ts
index e83f5d4..9b97190 100644
--- a/extension/src/service-worker/__tests__/session.test.ts
+++ b/extension/src/service-worker/__tests__/session.test.ts
@@ -28,10 +28,14 @@ describe('session', () => {
     expect(getCurrent()).toBeNull();
   });
 
-  it('clearCurrent() propagates exceptions from free()', () => {
+  it('clearCurrent() is best-effort: a throwing free() is swallowed, state is still cleared', () => {
+    // The security-zero path (clearAll) supersedes the old propagation
+    // expectation: one throwing handle must not abort zeroing the rest.
     const free = vi.fn(() => { throw new Error('boom'); });
     setCurrent({ free, value: 2 } as unknown as SessionHandle);
 
-    expect(() => clearCurrent()).toThrow(/boom/);
+    expect(() => clearCurrent()).not.toThrow();
+    expect(free).toHaveBeenCalledTimes(1);
+    expect(getCurrent()).toBeNull();
   });
 });
diff --git a/extension/src/service-worker/session.ts b/extension/src/service-worker/session.ts
index f47ad69..0ad0436 100644
--- a/extension/src/service-worker/session.ts
+++ b/extension/src/service-worker/session.ts
@@ -24,7 +24,16 @@ let context: 'personal' | string = 'personal';
 export function setPersonal(h: SessionHandle): void { personal = h; }
 export function getPersonal(): SessionHandle | null { return personal; }
 
-export function setOrg(orgId: string, h: SessionHandle): void { orgs.set(orgId, h); }
+export function setOrg(orgId: string, h: SessionHandle): void {
+  // Free any prior handle for this org before overwriting — otherwise a
+  // re-unlock of the same org would orphan the displaced handle, leaving its
+  // WASM key un-zeroed (the key only dies when .free() runs).
+  const prior = orgs.get(orgId);
+  if (prior && prior !== h) {
+    try { prior.free(); } catch { /* best-effort: keep going so the new handle still lands */ }
+  }
+  orgs.set(orgId, h);
+}
 export function getOrg(orgId: string): SessionHandle | null { return orgs.get(orgId) ?? null; }
 
 export function setContext(c: 'personal' | string): void { context = c; }
@@ -36,9 +45,20 @@ export function requireCurrentHandle(): SessionHandle {
   return h;
 }
 
+// The security-zero path. A vault lock or inactivity-timeout MUST zero every
+// handle it can, even if one .free() throws — so a single misbehaving handle
+// can never leave the others un-zeroed. Each .free() is wrapped in its own
+// try/catch (swallow + continue), and state is fully reset (personal nulled,
+// orgs cleared, context reset) REGARDLESS of any throw. This function never
+// throws.
 export function clearAll(): void {
-  if (personal) { personal.free(); personal = null; }
-  for (const [, h] of orgs) h.free();
+  if (personal) {
+    try { personal.free(); } catch { /* best-effort zero: keep going */ }
+    personal = null;
+  }
+  for (const [, h] of orgs) {
+    try { h.free(); } catch { /* best-effort zero: keep going */ }
+  }
   orgs.clear();
   context = 'personal';
 }