Facebook has discovered a massive security breach affecting 50 million user accounts – including those of Facebook boss Mark Zuckerberg and COO Sheryl Sandberg. What is a security breach?

“A security breach also known as a security violation, occurs when an individual or an application illegitimately enters a private, confidential or unauthorized logical IT perimeter.” Techopedia says.

Facebook said attackers exploited the site’s ‘View As’ feature, which lets people see what their profiles look like to other users.

The unknown attackers took advantage of a feature in the code called ‘Access Tokens,’ to take over people’s accounts, potentially giving hackers access to private messages, photos and posts – although Facebook said there was no evidence that had been done.

The hackers also tried to harvest people’s private information, including name, sex and hometown, from Facebook’s systems.

Facebook said it doesn’t yet know if information from the affected accounts has been misused or accessed and is working with the FBI to conduct further investigations.

However, Mark Zuckerberg assured users that passwords and credit card information was not accessed.

Because of the breach, the firm logged roughly 90 million people out of their accounts earlier today as a security measure.

Were you affected by the Facebook breach?

Affected users will be prompted to log back in Facebook when they try and access the site.

Users are sent a six-digit code via email or to a mobile device that authenticates their identity, which they’re then instructed to enter on Facebook’s site.

After they have logged back in, people will get a notification at the top of their News Feed explaining what happened.

Facebook also said it was temporarily turning off the ‘View As’ feature while it conducted a thorough security review.

Read the full story at dailymail.co.uk.