Pentagon DMDC Breach: 3M Military SSNs Exposed 9 Months
Pentagon DMDC Breach: 3M Military SSNs Exposed 9 Months File photo: An aerial view of the Pentagon in Arlington, Virginia. Photo: Master Sgt. Ken Hammond, U.S. Air Force (public domain). The institution charged with defending the United States could not defend its own filing cabinet. The Pentagon has confirmed that a breach of a file-sharing system at the Defense Manpower Data Center (DMDC) exposed unencrypted personnel records for roughly 3.05 million people — including the Social Security numbers, dates of birth, and in some cases the military occupational specialties of current and former U.S. service members. Unauthorized users had access to the files from October 2025 until the vulnerability was discovered and patched on July 16, 2026: roughly nine months of quiet, unnoticed access to one of the most sensitive personnel databases in the federal government. The news broke last week in Military Times and was confirmed Monday, September 28, by defense officials speaking to ...