

Updated on Septemat 1:08PM PT to include image of notification. After they have logged back in, people will get a notification at the top of their News Feed explaining what happened. As a result, around 90 million people will now have to log back in to Facebook, or any of their apps that use Facebook Login. We’re also taking the precautionary step of resetting access tokens for another 40 million accounts that have been subject to a “View As” look-up in the last year. Second, we have reset the access tokens of the almost 50 million accounts we know were affected to protect their security. First, we’ve fixed the vulnerability and informed law enforcement. Here is the action we have already taken. Access tokens are the equivalent of digital keys that keep people logged in to Facebook so they don’t need to re-enter their password every time they use the app. This allowed them to steal Facebook access tokens which they could then use to take over people’s accounts. But it’s clear that attackers exploited a vulnerability in Facebook’s code that impacted “ View As” a feature that lets people see what their own profile looks like to someone else. Our investigation is still in its early stages. We’re taking this incredibly seriously and wanted to let everyone know what’s happened and the immediate action we’ve taken to protect people’s security. On the afternoon of Tuesday, September 25, our engineering team discovered a security issue affecting almost 50 million accounts.
#Facebook session expired september 28 2018 update
Originally published on Septemat 9:41AM PT Security Update
