Apple rolled out iOS 26.4.2 to close a security gap that allowed the FBI to preview incoming Signal messages through push notification data left on devices.

Signal acknowledged the issue and thanked Apple for a rapid fix.

The flaw came to light during a federal trial, when investigators found message previews remained accessible because notification data was retained and only marked for deletion after the app was removed.

Users should review Settings to prevent retained notifications from exposing private chats.

The update automatically wipes stored notifications, so users don’t need to take extra steps.