BOOKOFF October hack exposes information on 6,383,279 members
Member information was leaked from BOOKOFF Corporation’s membership management system between October 4 and 6, 2026, and the company confirmed unauthorized access on October 6. The breach affected 6,383,279 members, exposing information including names, dates of birth, addresses, email addresses, phone numbers, and password hashes. The company blocked the attack route, individually notified affected members, and asked them to change their passwords.
Key facts
- Affected organization
- BOOKOFF Corporation
- Incident type
- Data breach
- Occurred / detected
- 2026-10-04
- Scale of damage
- Information on 6,383,279 members
- Cause / method
- Unauthorized access to the membership management system
- Location
- Japan
If your data was exposed
- Don’t tap links in texts, calls or emails that mention this incident and offer compensation, refunds or breach checks. Check directly on the organization’s official website or app.
Timeline
- Unauthorized access to the membership management system of a BOOKOFF Group Holdings subsidiary and the resulting leak of member information became public.
1 related reports
The summary and key facts are written by AI from related reports and may contain errors. Check the original articles and the organization’s official statements for accurate details.