2026 National Police Agency (Japan) — Arcadia cloud breach; ~125,000 police officers and staff at 20 prefectural forces
Data compromised
Staff safety-check system: names and email addresses of officers and staff at 20 prefectural police forces, and at some forces the organisational unit (for example Tochigi and Saitama). Security-alert system used by four forces: names and email addresses of about 16,000 individuals and 2,600 companies. Officials say the information “may have been compromised”.
Technical writeup
Disclosed by NPA officials on October 21, 2026. Reports differ on the number of forces (20 in the Japan Times and Jiji; 22 in Kyodo and Bernama). The date of the access is not stated, so the date field is the disclosure date. It is not confirmed whether this is the same intrusion as arcadia-speecan-raiden2026 (Arcadia SpeeCAN RAIDEN, October 11). recordsAffected 125000 is the approximate figure reported.
Root cause
Unauthorised access to cloud service operator Arcadia Inc., as described by NPA officials. The attacker, the method and whether any data was encrypted have not been published.