Facebook has today revealed that 50million accounts have been compromised in a security breach.
Attackers managed to exploit a feature that allowed to hack millions of Facebook user accounts.
The social networking giant has said they have fixed the vulnerability now and have informed law enforcement officials.
Facebook are investigating the security breach and have also taken precautionary measures.
The social networking giant has reset the access tokens for the almost 50million accounts affected by the breach.
Access tokens are the digital keys that keep people logged into Facebook so that they don’t need to re-enter their passwords.
As a precaution, another 40million Facebook users have had their Facebook access tokens reset.
So, in total around 90million Facebook users will today have to log back into Facebook or any apps that use a Facebook login.
Once they log back in they will get a notification at the top of their Facebook news feed explaining what happened.
If you have had to do that today then that means you’re one of those people affected by the Facebook breach.
If you haven’t had to do this then you’re unaffected by today’s major Facebook attack.
In a post online Guy Rosen, Facebook’s VP or Product Management, issued a statement about the data breach.
He said: “On the afternoon of Tuesday, September 25, our engineering team discovered a security issue affecting almost 50 million accounts.
“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.
“Our investigation is still in its early stages.
“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.
“This allowed them to steal Facebook access tokens which they could then use to take over people’s accounts.”
Rosen added: “This attack exploited the complex interaction of multiple issues in our code. It stemmed from a change we made to our video uploading feature in July 2017, which impacted “View As.”
“The attackers not only needed to find this vulnerability and use it to get an access token, they then had to pivot from that account to others to steal more tokens.
“Since we’ve only just started our investigation, we have yet to determine whether these accounts were misused or any information accessed.
“We also don’t know who’s behind these attacks or where they’re based.
“We’re working hard to better understand these details — and we will update this post when we have more information, or if the facts change. In addition, if we find more affected accounts, we will immediately reset their access tokens.”