Pentagon Begins Alerting Possibly Millions of Service Members About Personnel Database Breach

Just days after news broke of a massive breach at the FBI, the Pentagon is issuing warnings about a similar breach that resulted in hackers stealing data on millions of current and former service members.

TechCrunch reported on Wednesday that a user uploaded a breach notification letter to Reddit showing that their social security number, as well as other data, had been accessed by hackers who broke into the Defense Manpower Data Center (DMDC). That’s one of the main record-keeping systems for the military. CNN and the Federal News Network had both previously reported that the DMDC hack could affect over 3 million people (2.76 million alive, 294,000 deceased), though the Pentagon hadn’t started directly alerting service members.

Par for the course with this administration, service members are still flying blind on how widespread the breach actually is. The letter doesn’t specify how many soldiers are impacted. It does state that hackers had access to DMDC from October 2025 to mid-July 2026 and that the records had been stored unencrypted, which is a huge no-no. It also offered 12 months of credit monitoring.

As Cyber Security News noted, the roughly nine-month span of the reported breach is perhaps the most concerning bit so far. That suggests the attackers could have taken their time searching for data or spread laterally to other Pentagon-managed systems. Defense officials haven’t told media who the attackers were or their motives.

Officials have said that there is no evidence the information has been misused—but that’s going to be the case right up until the moment it is. There’s also no indication that this incident is related to the hack at the FBI, which recently dispatched the head of its cyber unit to trash-talk perpetrator ShinyHunters.