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JAENES
SSPossible leakOctober 23, 2026 announced

株式会社アンドエスティHDData 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
October 22, 2026
Announced on
October 23, 2026
Severity
SSLarge-scale compromise of sensitive data such as payment or identity-verification records affecting millions.
Scale
2,500,000 people
Main impact
Unauthorized access to business servers may have caused the leakage of approximately 2.5 million customers, about 10,000 business partners, and employee information. Stores and the web store continue to operate, but member points are unavailable.
Information involved
Email addressFull nameHome addressPhone number
Cause / key point
An incident in which unauthorized access to business servers led to intrusions into multiple servers and extraction of data.
Industry
Retail & e-commerce
Sources
Last updated
October 26, 2026

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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)

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