Sourcenext: mass leak of member data
Sourcenext detected abuse of its member-information API on October 13 and contained it by 13:36 that day. Its investigation found access from around 10:00 on October 9 and possible exposure of up to 22,519,960 records. Fields vary by registration and include names, emails, passwords, addresses, genders, phone and fax numbers, birth dates, employer details, service enrollment and registration/login dates. Card data was not stored in the affected system. Affected passwords were invalidated and an independent investigation continues.
Disclosed
2026-10-15
Organizations involved
1
Leaked or at risk
22.5M
22,519,960
Downtime
Unknown
Timeline
- Started 2026-10-09
- Detected 2026-10-13
- Disclosed 2026-10-15
- 6 days
Attack or cause
- Method
- [API abuse]
- Impact
- [Data leak]
- Entry point
- API
Data exposed or at risk
Organizations involved
[Breached][Critical]Tokyo, ChiyodaInformation and communications22,519,960 leaked
Sourcenext Corporation
Sources
- [1][Official]不正アクセスによる個人情報流出に関するお知らせSourcenext · 2026-10-15
- [2][News]ソースネクスト、不正アクセスでパスワード含む会員の個人情報最大約2252万件が流出INTERNET Watch · 2026-10-16
- [3][Official]情報漏洩に関するよくあるご質問Sourcenext