US Dept of Defense Data Breach History
WebsiteThe United States Department of Defense is the federal department responsible for the military.
This page shows all data breaches of US Dept of Defense. View the complete breach timeline, records exposed, root causes, and AI breach risk score. BreachHistory tracks disclosed data breaches worldwide.
Data Breach Timeline — All US Dept of Defense Breaches
US Dept of Defense Data Breach Summary
This page tracks the US Dept of Defense data breach history and cybersecurity incidents affecting US Dept of Defense (United States). BreachHistory currently indexes 1 publicly disclosed or catalogued incident spanning 2009, with approximately 72 thousand 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 US Dept of Defense 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.
Largest US Dept of Defense Data Breaches
The largest indexed incidents include the 2009 — US Dept of Defense: According to a report to Congress, assessment forms…. Record counts originating from threat actors or leak sites should be treated as estimates unless confirmed by US Dept of Defense or a regulator. Below is the list of large data breaches:
- 2009 2009 — US Dept of Defense: According to a report to Congress, assessment forms… — about 72.0K records exposed · Catalogued incident
What Information Was Exposed?
Depending on the incident, exposed data may include email addresses, passwords, phone numbers, names, profile information, account identifiers, and other personal information (PII). The exact data varies between incidents, so review each breach page before assuming your information was affected.
US Dept of Defense Data Breach 2026
At the time of this update, no US Dept of Defense 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 US Dept of Defense 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 US Dept of Defense 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.