ソースネクストData breach / unauthorized access incident
- Occurred on
- October 9, 2026
- Announced on
- October 15, 2026
- Severity
- SSLarge-scale compromise of sensitive data such as payment or identity-verification records affecting millions.
- Scale
- 22,519,960 records
- Main impact
- The company announced that 22,519,960 member records were leaked due to unauthorized access to the system that manages member information. The leaked data is said to include email addresses, passwords, names, addresses, phone numbers, dates of birth, company names, etc.; all passwords have been invalidated and must be reset. Credit card information is excluded because it does not exist in the affected system.
- Information involved
- Email addressUser / member IDPasswordPhone numberHome addressFull nameDate of birth
- Cause / key point
- The company announced that member information was obtained via unauthorized access caused by a third party illicitly using the member information retrieval API; the incident occurred around 2026年10月9日, was detected and contained on 10月13日, and the details of misuse are being investigated with external specialists.
- Industry
- IT & telecom
- Sources
- Last updated
- October 22, 2026
Is this incident worth paying attention to?
Written & reviewed
Reviewed byYutaro SasaoFounder & CEO, MediaLeap Inc.
CEO of MediaLeap Inc. Working on both sides of web advertising and web media since 2013; founded the company in May 2025.
Review scope: cross-checking against primary sources (official and government announcements), verifying claims stay within the facts, and checking source attribution。Last reviewed:
Written by:Leak Watch editorial team (AI-assisted drafts verified against sources by the editorial team) · Reviewer profile · Request a correction
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Attack method classification: Unauthorized access (method undisclosed)(Breached, but the technique was not identified or disclosed)
Read the Unauthorized access (method undisclosed) guide and national trends →