South Korea's Military Medical Imaging System Breach Exposes Data of 1.15 Million Personnel

South Korea's Defense Ministry confirmed that an unauthorized party accessed the military's mobile medical imaging storage and transmission system (PACS) via an open network port that remained exposed from November 2025 to March 2026. Approximately 8 GB of data—about 1,000 radiology images—related to the medical records of roughly 1.15 million service members were accessed, affecting six military hospitals in Goyang, Yangju, Pocheon, Gangneung, Guri and Daegu. No definitive evidence of data exfiltration has been found, and the Ministry has halted the mobile PACS service since 14 April 2026 while investigating and planning preventive measures. Three active-duty medical officers are undergoing disciplinary procedures for their role in the system’s security lapse.

In a related incident, hackers breached the Korea National Diplomatic Academy’s online education platform, compromising between 6,000 and 10,000 records of current and former diplomats, including email addresses, usernames and encrypted passwords. The Foreign Ministry responded by changing all diplomatic email accounts and shutting down the compromised system pending investigation. Both breaches underscore shortcomings in South Korea’s cyber‑defense posture and have prompted a broader security review.