The bug was first discovered earlier this month by Twitter user and software tester Neo QA, who tweeted video evidence of the issue. Since then more users have taken to social media to report the same thing.
The footage shows the app activating the camera once a Facebook user taps into a photo or video in fullscreen mode. And when user try to close the photo or video, the camera remains open, hiding behind the Facebook feed.
Another Twitter user, Joshua Maddux shared evidence of the same bug and later confirmed the issue was present on multiple iPhones he tested.
Yesterday, Facebook's VP of Integrity Guy Rosen has addressed the issue, tweeting that the team is now working on fixing it, promising an update to the App Store coming soon.
Facebook also submitted an official quote to Mashable, reiterating the fact that this was an inadvertent mistake which the company plans on fixing immediately.