diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6b5c41be1..10da312cd 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ Docs: https://docs.openclaw.ai
 ### Fixes
 
 - Security/Canvas: serve A2UI assets via the shared safe-open path (`openFileWithinRoot`) to close traversal/TOCTOU gaps, with traversal and symlink regression coverage. (#10525) Thanks @abdelsfane.
+- Security/WhatsApp: enforce `0o600` on `creds.json` and `creds.json.bak` on save/backup/restore paths to reduce credential file exposure. (#10529) Thanks @abdelsfane.
 - Security/Gateway + ACP: block high-risk tools (`sessions_spawn`, `sessions_send`, `gateway`, `whatsapp_login`) from HTTP `/tools/invoke` by default with `gateway.tools.{allow,deny}` overrides, and harden ACP permission selection to fail closed when tool identity/options are ambiguous while supporting `allow_always`/`reject_always`. (#15390) Thanks @aether-ai-agent.
 - MS Teams: preserve parsed mention entities/text when appending OneDrive fallback file links, and accept broader real-world Teams mention ID formats (`29:...`, `8:orgid:...`) while still rejecting placeholder patterns. (#15436) Thanks @hyojin.
 - Security/Audit: distinguish external webhooks (`hooks.enabled`) from internal hooks (`hooks.internal.enabled`) in attack-surface summaries to avoid false exposure signals when only internal hooks are enabled. (#13474) Thanks @mcaxtr.
diff --git a/src/web/auth-store.ts b/src/web/auth-store.ts
index 3b535eb82..e98e48b67 100644
--- a/src/web/auth-store.ts
+++ b/src/web/auth-store.ts
@@ -68,6 +68,11 @@ export function maybeRestoreCredsFromBackup(authDir: string): void {
     // Ensure backup is parseable before restoring.
     JSON.parse(backupRaw);
     fsSync.copyFileSync(backupPath, credsPath);
+    try {
+      fsSync.chmodSync(credsPath, 0o600);
+    } catch {
+      // best-effort on platforms that support it
+    }
     logger.warn({ credsPath }, "restored corrupted WhatsApp creds.json from backup");
   } catch {
     // ignore
diff --git a/src/web/session.ts b/src/web/session.ts
index c25d6d793..c02f59388 100644
--- a/src/web/session.ts
+++ b/src/web/session.ts
@@ -73,6 +73,11 @@ async function safeSaveCreds(
       try {
         JSON.parse(raw);
         fsSync.copyFileSync(credsPath, backupPath);
+        try {
+          fsSync.chmodSync(backupPath, 0o600);
+        } catch {
+          // best-effort on platforms that support it
+        }
       } catch {
         // keep existing backup
       }
@@ -82,6 +87,11 @@ async function safeSaveCreds(
   }
   try {
     await Promise.resolve(saveCreds());
+    try {
+      fsSync.chmodSync(resolveWebCredsPath(authDir), 0o600);
+    } catch {
+      // best-effort on platforms that support it
+    }
   } catch (err) {
     logger.warn({ error: String(err) }, "failed saving WhatsApp creds");
   }