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JAENES
APossible leakOctober 13, 2026 announced

綾瀬市（安全・安心メール）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
Unconfirmed
Announced on
October 13, 2026
Severity
AFinancial and HR records — information that easily translates into monetary damage.
Scale
11,053 people
Main impact
綾瀬市 has announced that due to unauthorized access to the 安全・安心メール system, the information of 11,053 registered users may have been leaked.
Information involved
Email addressHome addressFull name
Cause / key point
Unauthorized access to the system.
Industry
Government & municipal
Listing / capital
Government / public body
Sources
Last updated
October 20, 2026
Email addressHome addressFull nameHow severity is assessed →

Is this incident worth paying attention to?

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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