The company did not reveal whether these hacked accounts were misused.
Facebook said they have reset the access token to nearly 50 million accounts that they know were affected by the breach. The Facebook users have been suggested, in this matter, in view of recent reports that access tokens of 5 Crore users have been stolen by hackers. Facebook is now investigating the origins of the hack and the scale on which it was conducted.
Facebook on its newsroom page posted a almost 900-words report informing about a new security breach on September 28.
Facebook says access tokens, not passwords, were stolen. This was not too long ago, and 70 million accounts were compromised as a result.
The company then stated that the source of the vulnerability, the "View As" feature, has been disabled for the time being, adding that the feature became open to attack in July 2017 when Facebook edited its video uploading.
The social media giant's revealed attackers exploited the "view as" feature in July previous year - which lets you see your profile as others do.
Damian Collins, who chairs the select committee, said: "Facebook's latest data breach demonstrates more clearly than ever why Mark Zuckerberg should face public scrutiny about the practices and policies his company employs to keep British users' data safe".
Experts say the impact could be far-reaching because beyond Facebook, hackers could have accessed any account logged into using Facebook. The company also has reset access tokens for the affected accounts and another 40 million accounts that have have used the "View As" feature in the past year. After they have logged back in, people will get a notification at the top of their News Feed explaining what happened. It would be disingenuous to pretend that the concerns driving the backlash against Facebook are totally bipartisan, but the network has tread well into unsafe territory - and if it turns out attackers gained access to and misused sensitive user data, it could get much worse, quickly.
The Wall Street Journal has reported that Ireland's Data Protection Commission, the leading entity that looks over Facebook for the European Union, has asked for more information pertaining to the hack.
What can you do to protect your Facebook account?
Moreover, you can uninstall the Facebook app and re-install it later, for that will ensure your old authentication tokens are lost.
The law also requires companies to notify regulators of breaches within 72 hours, under threat of a maximum fine of 2 per cent of world-wide revenue. "The access tokens have been compromised and Facebook has force re-set access token now". Campbell said you should always use it with caution. This is a list of devices where you won't have to use a login code. More importantly, this feature protects your account from any attackers, even if they have your password.