A new Siri bug first reported by Brazilian site Mac Magazine allows users to hear messages from third-party apps to be read from a locked iPhone.
Apple’s own Messages app isn’t affected. But the bug will allow anyone to hear complete messages from other third-party messaging apps like Skype or WhatsApp.
The site did confirm that the bug was present in both iOS 11.2.6 and the latest iOS 11.3 beta.
With iOS 11, users can have the complete message notifications to be hidden on a lock screen and only appear when unlocked. It’s the default setting for the iPhone X as you can view the complete content and unlock the phone with Face ID.
Before Apple offers a fix, the best way to tackle the issue is to completely disable Siri when you’re device is locked. Go to Settings > Siri & Search and toggle Allow Siri When Locked to off.