Based on a report, the passwords of millions of Facebook users were accessible by up to 20,000 employees of the social network.
According to security researcher Brian Krebs, who broke the data protection failure reports, which saw up to 600 million passwords stored in plain text, as he claims.
The passwords that were exposed could date back to 2012, Krebs said.
In a statement, Facebook said it had now resolved a “glitch” that had stored the passwords on its internal network.
In a detailed expose, Krebs said a Facebook source had told him about “security failures” that had let developers create applications that logged and stored the passwords without encrypting them.
Commenting on Krebs’s story Facebook engineer, Scott Renfro said an internal investigation started after Facebook had uncovered the logs had not revealed any “signs of misuse”.
And its investigation showed that most of the people affected were users of Facebook Lite, which tends to be used in nations where net connections are sparse and slow.
“We estimate that we will notify hundreds of millions of Facebook Lite users, tens of millions of other Facebook users, and tens of thousands of Instagram users,” the company told Reuters.
In September last year, it said information on 50 million users had been exposed by a security flaw.
Furthermore, earlier in 2018, it revealed that data on millions of users had been harvested by data science company Cambridge Analytica.