Data Leak at the Pentagon Affects Over 3 Million Military and Civilian Employees

A data breach at the U.S. Department of War has affected more than 3 million people associated with the U.S. Armed Forces.

ABC News reported on this.

The exposed information includes Social Security numbers and details about the positions held by military and civilian personnel. The breach affected 2.76 million living individuals and approximately 294,000 deceased individuals.

Unauthorized access to the system lasted from at least October 2025 through July 2026. The Pentagon stated that a small number of unauthorized users gained access to the data.

On July 16, 2026, military personnel discovered an issue in the file-sharing system.

After an investigation, investigators determined that unauthorized users could view files containing unencrypted personal information.

The U.S. Department of War’s Manpower Data Center (DMDC) stores information on more than 60 million people. This database includes active-duty and reserve service members, civilian employees, veterans, retirees, contractors, and members of military families.

The Pentagon stated that it currently has no evidence that the stolen data has been used for criminal purposes. Those affected are being offered identity protection and credit monitoring services.

In 2024, the Chinese hacking group Salt Typhoon also gained access to the network of one of the U.S. National Guard’s units.

The attack lasted from March to December 2024, and sensitive data—including maps and information on network traffic—was stolen from the systems. U.S. officials linked the group to Chinese cyberintelligence.

Meanwhile, the current data breach at the Defense Manpower Data Center has not yet been officially linked to a specific country or hacking group.

The Pentagon reported only that a small number of unauthorized users gained access to files between October 2025 and July 2026.

Amid this incident, other recent attacks on U.S. government agencies are also drawing attention. In September 2026, the ShinyHunters hacking group claimed to have executed a large-scale data theft from FBI systems.

U.S. law enforcement agencies are investigating this incident, but have not linked it to the DMDC breach.