Washington, DC, October 1, 2026 Hackers Breach Pentagon’s Defense Manpower Data Center, Exposing Sensitive Information of Over 3 Million In a shocking turn of events, the U.S. Department of Defense has acknowledged a nine-month-long data breach at the Defense Manpower Data Center (DMDC), exposing sensitive personal information of more than 3 million individuals. The breach, which occurred between October of the previous year and July of the current year, involved unauthorized access to data relating to 2.76 million living individuals and approximately 294,000 deceased individuals.
The intrusion targeted Social Security Numbers (SSNs), personally identifiable information identifying military and civilian personnel, and military occupational data such as functions, ranks, positions, and specialties assigned within the Armed Forces. The threat actors exploited a vulnerability in a file-sharing system to gain entry and navigate freely through the affected server, accessing confidential files hosted thereon.
Following confirmation of the incident, senior U.S. defense and cybersecurity officials implemented immediate measures to patch the software vulnerability used in the attack and to strengthen access protocols to personnel data. A Pentagon spokesperson stated there is currently no evidence that the exposed information has been misused. The Department of Defense has initiated a notification process for affected individuals and is collaborating with cybersecurity agencies to determine the full extent and potential culprits of the cyberattack, though their identities have not been disclosed.
Government agencies have issued internal security warnings, as described by networks including ABC News, instructing affected personnel not to speak with the media, to remain alert to suspicious calls, and to immediately call 911 if journalists are observed committing trespassing or intrusion on private property. The incident underscores risks associated with the compromise of professional and military information, particularly given the sensitivity of data managed by the DMDC, which supports personnel and payroll operations across the Department of Defense.
