An attack on Facebook's computer network has exposed the information of nearly 50 million users, the company said Friday.
According to a report by The New York Times, Facebook found the breach earlier this week. Hackers had used a part of the social media platform's code to take over user accounts.
Facebook has fixed the vulnerability and informed law enforcement officials of the breach, the company said.
It has yet to determine whether these accounts were misused or any information was accessed, it added.
To deal with the issue, Facebook reset some logins, so 90 million people have been logged out and will have to log in again. That includes anyone who has been subject to a "View As" lookup, the feature which was exploited, in the past year.
Facebook says it doesn't know who's behind the attacks or where they're based.
News broke early this year that a Trump-linked data analytics firm, Cambridge Analytica, had gained access to personal data from millions of user profiles. Then a congressional investigation found that agents from Russia and other countries have been posting fake political ads since at least 2016. Facebook CEO Mark Zuckerberg appeared at a Congressional hearing over Facebook's privacy policies in April.
In a call with reporters on Thursday Zuckerberg said that the company doesn't know yet if any of the accounts that were hacked were misused.
Facebook has more than 2 billion users worldwide.
