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JAENES
APossible leakSeptember 7, 2026 announced

コープやまぐち（LINEミニアプリ）Data breach / unauthorized access incident

笹尾 祐太朗の写真Reviewed by Yutaro SasaoWritten by Leak Watch editorial team published ・ updated
Occurred on
August 27, 2026
Announced on
September 7, 2026
Severity
AFinancial and HR records — information that easily translates into monetary damage.
Scale
212,712 accounts
Main impact
A LINE mini app database was unlawfully accessed, and information on 212,712 registered cooperative members (including cardholders) may have been exposed.
Information involved
Card & payment data
Cause / key point
Unauthorized third‑party access to the database. The cause is under investigation.
Industry
IT & telecom
Listing / capital
Non-profit corporation

Consumer cooperative (co‑op)

Sources
Last updated
October 20, 2026
Card & payment dataHow severity is assessed →

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Written & reviewed

笹尾 祐太朗の写真

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 →

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