Tumblr Data Breach History

This page tracks the Tumblr data breach history and cybersecurity incidents affecting Tumblr. BreachHistory currently indexes 4 publicly disclosed or catalogued incidents spanning 2013 through 2016, with approximately 260.9 million records reported as exposed across all indexed events. These totals may include overlapping datasets or third-party estimates and should not be interpreted as unique affected users.

The Tumblr breach timeline includes major data breaches, cyber attacks, data leaks, credential exposures, API abuse, and other security incidents. Each incident provides details on the estimated records exposed, attack method, affected data types, and supporting public sources. Currently, 0 incidents are company-confirmed, while 1 remain unverified claims pending independent verification.

Largest Tumblr Data Breaches

The largest indexed incidents include the 2013 — Tumblr: Hacking, 65,469,298 records, the 2013 Tumblr — 65.5M accounts, and the 2016 — Tumblr: Tumblr claimed it just found out about a 2013 data…, along with additional historical incidents involving exposed passwords, public databases, and large-scale data scraping. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by Tumblr or a regulator. Below is the list of large data breaches:

• 2013 2013 — Tumblr: Hacking, 65,469,298 records — about 65.5M records exposed · Catalogued incident
• 2013 2013 Tumblr — 65.5M accounts — about 65.5M records exposed · Catalogued incident
• 2016 2016 — Tumblr: Tumblr claimed it just found out about a 2013 data… — about 65.0M records exposed · Unverified claim
• 2013 2013 — Tumblr: Tumblr apparently only just found out about a 2013… — about 65.0M records exposed · Catalogued incident

What Information Was Exposed?

Depending on the incident, exposed data may include email addresses, passwords and login credentials, physical addresses, health and medical (PHI) records, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.

Tumblr Data Breach 2026

At the time of this update, no Tumblr data breach has been catalogued for 2026. New incidents are added as official disclosures, regulatory filings, or credible cybersecurity reports become available.

What To Do If You Were Affected

If you believe your account may have been involved in a Tumblr data breach, change any reused passwords, enable multi-factor authentication (MFA), monitor your account for suspicious activity, and be cautious of phishing emails or fake breach notifications.

This Tumblr breach history is maintained by BreachHistory using public disclosures, regulatory filings, security research, and clearly labelled third-party claims. For the complete breach timeline, records exposed, incident details, and AI Breach Risk Score, explore the sections on this page.