Japan: Data Breach Incidents by Country / region

Search incidents by company, country, industry, year and attack method. Review affected data, impact, verification status, company responses and sources.

767 results
Investigating

Mandarake: server intrusion may have exposed mail-order customers’ shipping data

Possible data leak: Unauthorized server access confirmed Aug 27, 2026; services paused and a status page published around Aug 30. Intrusion into a shipping-info server was confirmed, but the Oct 28 final report found no evidence of viewing/exfiltrating DB personal data.

Investigating

Co-op Yamaguchi: LINE mini-app DB intrusion may have exposed member and related data

Possible data leak: Unauthorized access to the Co-op Yamaguchi LINE mini-app disclosed Aug 28, 2026. Second report listed several category counts (members with/without e-money cards, reservation users, etc.). Cards, bank accounts, passwords and sensitive personal data out of scope.