Facebook's latest data breach impacts up to 50 million accounts

If you’re wondering why Facebook asked you to put in your password for the first time in decades today, it’s because the social media juggernaut experienced a security breach impacting nearly 50 million user accounts. In a blog post, VP of Product Management Guy Rosen says “the 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.” So, if you’ve confirmed recently that Grandma can’t see your weed statuses, you’ve probably been affected.

Rosen continues:

This allowed them to steal Facebook access tokens which they could then use to take over people’s accounts. 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.

Here is the action we have already taken. First, we’ve fixed the vulnerability and informed law enforcement.

Related Content

• Court filing says Zuck knowingly okayed training Facebook's AI on pirated books
• Apparently, fact-checking is now too political for Facebook

Second, we have reset the access tokens of the almost 50 million accounts we know were affected to protect their security. 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. 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. After they have logged back in, people will get a notification at the top of their News Feed explaining what happened.

Third, we’re temporarily turning off the “View As” feature while we conduct a thorough security review.

Rosen adds that the nature of the attack is still unknown, as is “whether these accounts were misused or any information accessed.”

The breach follows a much larger one reported earlier this year, in which a consulting firm working with Donald Trump’s presidential campaign had used an app to pull profile data from 87 million of the site’s users.

But, hey, at least they’re actually telling us about this one!