Data breaches → tumblr
Was your data in the tumblr breach?
2013 · tumblr.com · ~65,469,298 accounts exposedCritical severity · 10/10
tumblr (tumblr.com) suffered a data breach in 2013 that exposed around 65,469,298 accounts. If you had an account, some of your personal data may be circulating in leaked databases. The fastest way to know is to check your own email — free, in about 30 seconds, no password required.
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 details sourced from Have I Been Pwned, the industry-standard breach database. Risk analysis by Nullivo.
What was exposed, and why it matters
Not all breaches carry the same risk — what matters is which fields leaked. Here is what the tumblr breach exposed and what each item actually enables:
Attackers replay leaked passwords across other sites (“credential stuffing”). Because most people reuse passwords, one leak often unlocks email, shopping and banking accounts elsewhere.
Puts you on spam and phishing lists, and confirms to attackers that you hold an account with this service — which makes impersonation emails more believable.
What to do if you were affected
These steps are ordered for this specific breach — the most urgent action given what leaked comes first.
- Passwords: Change this password everywhere you have reused it, starting with your email account — whoever controls your email can reset everything else.
- Email addresses: Treat any message referencing this service with suspicion, and never act on links in unexpected emails.
- Check whether your own email appears in this breach — run a free scan to confirm before you spend time on the steps above.
How urgent is this now?
This breach is over 13 years old. Old credentials still cause harm — leaked passwords from a decade ago are still tried against new accounts every day.
Passwords are the reason breach age matters less than people expect. Leaked credentials are compiled into wordlists that get tried against new services for years afterwards, so a password exposed here is unsafe to use anywhere, ever again.
Remember: a breach can't be "un-leaked" — once a database is out, it exists in countless copies. The goal is to make the leaked data useless: change what can be changed, lock down what can't, and remove what has been republished.
Frequently asked questions
What data was exposed in the tumblr breach?
The tumblr breach exposed passwords, email addresses. Attackers replay leaked passwords across other sites (“credential stuffing”). Because most people reuse passwords, one leak often unlocks email, shopping and banking accounts elsewhere.
How many people were affected by the tumblr breach?
Around 65,469,298 accounts were exposed, making it a very large breach by any measure.
What should I do if I had a tumblr account?
Change this password everywhere you have reused it, starting with your email account — whoever controls your email can reset everything else. You can check whether your own email appears in this breach with a free Nullivo scan — no password required.
Breaches that exposed similar data
If the tumblr breach affected you, these breaches exposed comparable information — worth checking too, since leaked datasets are routinely combined.
- Was your data in the JD breach? (2013, ~77,449,341 accounts)
- Was your data in the iMesh breach? (2013, ~49,467,477 accounts)
- Was your data in the Evite breach? (2013, ~100,985,047 accounts)
- Was your data in the Adobe breach? (2013, ~152,445,165 accounts)
- Was your data in the Neopets breach? (2013, ~26,892,897 accounts)
- Was your data in the Dropbox breach? (2012, ~68,648,009 accounts)