Facebook says 50M users were affected by breach

Nearly 50 million Facebook accounts have been affected by a security breach that enabled hackers to take over users’ accounts, the social media giant announced Friday.

The new breach comes as Facebook strives to convince its more than 2 billion users that it can be trusted. It is grappling with the fallout from the revelation that British consulting firm Cambridge Analytica harvested the personal data of up to 87 million users, as well as the revelation that it unwittingly played host to a massive Russian misinformation campaign during the 2016 U.S. elections.

The new vulnerability was discovered Tuesday afternoon and has been patched, Facebook said.

“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,” the company said Friday in an online post. “This allowed them to steal Facebook access tokens” — which gave attackers full access to user profiles, as if the hackers were those users.

"This is a really serious security issue, and we’re taking it really seriously,” Facebook Chief Executive Mark Zuckerberg told reporters on a phone call Friday.

No password or credit card data were stolen, Guy Rosen, Facebook vice president of product management, told reporters. He said it was unclear whether the attackers had accessed private messages or posts and whether they had posted from hacked accounts.