After the Facebook worker discovered the bug, the company changed the privacy settings of the post uploaded by 14 million affected users, from the public to private.
Facebook changes the privacy settings of all affected posts to private, even posts that may be shared publicly. They said they needed five days to make the change.
Users affected by this bug will get notifications on their Facebook app or site starting on Thursday. They will get messages from Facebook, asking them to "review your uploads", complete with links to the list of postings they upload when the bug is active.
The Facebook content privacy settings will follow the last post user privacy settings, such as friends, family or colleagues. However, the setting changed automatically to the public for 14 million users. If the user is aware of the change of settings, they can change the privacy settings manually.
"We just found a bug that automatically advises users to upload posts publicly when they upload content on Facebook," said Chief Privacy Officer of Facebook, Erin Egan.
"We have solved this problem and starting today we will notify people affected by this bug and ask them to review posts they upload in periods when the bug is active."