Seicomart Data Breach
Hokkaido-based Japanese convenience store operator Seicomart Co., Ltd. disclosed in October 2026 that the backend system supporting its official Seicomart Club smartphone app experienced unauthorized external access on September 29, 2026.
Exposed Data Types
7- Names
- Dates of birth
- Genders
- Physical addresses
- Phone numbers
- Email addresses
- User IDs
About This Breach
Forensic analysis showed that personal details associated with approximately 570,000 registered app accounts were potentially exposed.
Compromised fields included full names, dates of birth, gender markers, postal addresses, telephone numbers, email addresses, and Seicomart Club / Pecoma membership numbers. Seicomart confirmed that electronic money balances, PINs, and credit card details were not stored on the affected server.
Verification and editorial method
LeakData compares the incident name, date, affected-record count, and exposed data types with accessible sources. Unverified fields are not presented as facts, and records are updated when new evidence becomes available.
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