With Apple's notification system, users have the choice of displaying a preview of the notification when they receive it, or hiding it so that anyone who glances at their phone won't be able to see the contents of the notification until they unlock their device.
According to Reuters, which was provided copies of Apple's developer agreement, app makers have to get "clear and conspicuous consent" from users before collecting or storing face data, and can only do so for a "legitimate feature" of an app. So till this bug is active, Siri can read out all notifications on the iPhone X even without the owner's permission.
"We are aware of the issue and it will be addressed in an upcoming software update", Apple said in a statement provided to MacRumors on Thursday.
Apple has acknowledged the problem and promised a fix soon.
But the feature has been around for a while, previously allowing users to manually change their settings to hide notification previews. With the existence of the bug, most of the notifications on iPhone X can be read out loud without requiring owner's permission.
In order to disable Siri on the lock screen, head to Settings Siri & Search Allow Siri When Locked.
But a number of websites tested the iPhones, and found that Siri would gladly read out all messages when asked.
Siri was launched alongside the iPhone 4s in 2011.
To disable notifications for apps, you need to go to Settings, then select Notifications. Apparently, this setting correctly stops Siri from reading out messages at the lockscreen.
Another option is to turn off lock screen notifications to apps you think to carry sensitive information.