This bug had the potential to expose the email address and phone number associated with a Vine account to third parties under certain circumstances.
We understand that this issue would not have affected Twitter users who didn't also have Vine accounts, though. It's also advising affected users to be cautious about any emails from unknown senders as a result.
Emails are now going out to affected users, and will be personalized in terms of whether the user had only their email, only their phone number, or both exposed during the time the vulnerability was live.
Vine said late Friday afternoon that a "bug" had affected an archive that was erected after Twitter shuttered the six-second video app in January.
Twitter told users it had not been hacked and it is not considering the incident a data breach.
An investigation turned up the identities of the accounts which have had exposed information, though the company is at pains to point out that accounts themselves weren't compromised. If you see a message from Twitter in your inbox, you may want to take a look. And who on your friends list is still using AIM?
Twitter noted that thus far it has no reason to believe the information has been misused, but said Vine only sends communications with users from the @twitter.com domain and never sends emails with attachments or requests for a user's password.
Vine has been dead for almost five months and users have likely moved on from it, forgetting all about the six-second looping videos that populated it. Millions of users were unable to access the service throughout the day, including many in the eastern U.S., Europe and Japan. No password data was taken and Twitter has not seen any indication that the exposed data was misused in any way.