Breach date: 2013-02-28. Added to this index: 2016-05-29. Accounts affected: about 65M. Domain: tumblr.com.
What happened
In early 2013, tumblr suffered a data breach which resulted in the exposure of over 65 million accounts. The data was later put up for sale on a dark market website and included email addresses and passwords stored as salted SHA1 hashes.
Breach data sourced from Have I Been Pwned, used under CC BY 4.0. Additional breach metadata provided by XposedOrNot. DataExposed is an independent service and is not affiliated with or endorsed by either.
What was exposed
Email addresses: The email address you used to register or log in. It is the most common field in breaches because it doubles as your username on most sites.
Passwords: The secret you use to sign in, stored by the breached service either in plain text, in a scrambled form called a hash, or encrypted. How it was stored decides how quickly it can be recovered.
What to do now
Check whether your own address is in this dataset with the free email breach check.
Change the password on this service and every other site where you used the same password.
Turn on two-factor authentication on your email account first, because it is the reset path for everything else.
Treat calls and messages that quote real details about you as hostile until you verify them another way.
Frequently asked questions
What data was leaked in the tumblr breach?
The tumblr breach exposed Email addresses, Passwords. About 65M accounts were affected.
Was I affected by the tumblr breach?
Run the free email breach check with the address you used on that service. It will tell you whether your address appears in this dataset.
What should I do about the tumblr breach?
Change the password on that account and everywhere you reused it, then turn on two-factor authentication. Passwords from this breach are traded and tried automatically against other sites.