A programming bug in Facebook website accidentally gave 1,500 third-party apps access to unposted Facebook photos of as many as 6.8 million users. The bug even exposed photos that people uploaded to Facebook but chose not to post or didn’t finish posting it for some reason. The flaw left users’ private data exposed for 12 days, between September 13th and September 25th, until Facebook discovered and fixed the security blunder on the 25th September. The social media giant has started notifying impacted users of the flaw through an alert on their Facebook timeline that their photos may have been exposed.
Source: https://thehackernews.com/2018/12/facebook-api-bug-leak.html