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coop-yamaguchi-2026 · Disclosed 2026-08-28

コープやまぐち: unauthorized access and impact

The outsourced mini-app database was accessed and deleted; this was not a LINE Yahoo database incident. The four affected datasets contain 69,586, 143,126, 365 and 4,218 records; the 217,295-record total describes potential scope, not confirmed theft.

Supply chain / CICause unresolved / undisclosed

Outcome: Confirmed breach

Entry path and evidence

  • Reported fact

    The outsourced mini-app database was accessed and deleted; this was not a LINE Yahoo database incident.

    [s1]第2報 §§1,2,5
  • Reported fact

    The four affected datasets contain 69,586, 143,126, 365 and 4,218 records; the 217,295-record total describes potential scope, not confirmed theft.

    [s1]第2報 §§1,2,5

Timeline

  1. Event date reported by the source. [s1]

  2. Disclosure date established by the reviewed notice. [s1]

Reported response

  • Reported fact

    Access was blocked, credentials changed and the database restored from backup.

    [s1]第2報 §§1,2,5

Evidence relevant to prevention

Insufficient evidence

Undisclosed entry or patch timing prevents an avoidability assessment. Inspect privileges, retrieval logs, retention and deployed configuration using the linked rules.

Editorial assessment; not a determination of liability. [s1]

Unknowns and AI involvement

AI involvementUnknown

The reviewed disclosures do not establish attacker use of AI.

The entry route and exfiltration remain under investigation.

Sources

  1. [s1] コープやまぐち · Primary source

    コープやまぐち：事故に関する公表資料 ↗

    Reviewed 2026-10-09