Incident BriefingsJapan Digital Agency GSS unauthorized access

Japan Digital Agency GSS unauthorized access

Japan’s Digital Agency confirmed unauthorized access to Government Solution Service (GSS).

Last modified

Summary

  • Environment: Government Solution Service
  • Operational impact: Compromised account suspended and device isolated
  • Financial impact: No incident cost established in the reviewed evidence
  • Record status: Developing record. Reviewed October 7, 2026; updated as evidence emerges.

What happened

Japan’s Digital Agency confirmed unauthorized access to Government Solution Service (GSS). [1]

Impact

Approximately 246,000 personal-information records potentially leaked, involving government personnel and work contacts. [1]

Timeline

  1. Anomalous access detected

    Mass file access triggered investigation.

    [1]

  2. Compromise confirmed

    Investigators confirmed intrusion and isolated access.

    [1]

  3. Public disclosure

    The agency published its notice.

    [1]

  4. Briefing updated

    This briefing was last reviewed and updated on October 7, 2026.

Threat Group & Attack Vector

The agency identified exploitation of a VPN-device vulnerability. [1]

Actors

  • No threat actor group has been identified in the reviewed public evidence.

TTPs

  • No specific MITRE ATT&CK technique is currently mapped for this case.

Response

It suspended the compromised account, isolated the device and planned individual notifications. [1]