Twitter has recommended its more than 336 million users change their passwords.
The company announced on Thursday it discovered a bug that saved user passwords on an internal log without proper encryption.
Twitter said it has since fixed the issue. Although the company said there is no evidence passwords have been leaked or misused, it is urging its users to update their passwords.
"As a precaution, consider changing your password on all services where you've used this password," the company tweeted.
Twitter did not specify how many passwords were stored in the internal log.
The company did not immediately respond to a request for comment.