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JAENES
CPossible leakOctober 13, 2026 announced

島田市（島田市防災メール）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
CLimited data such as email addresses and identifiers.
Scale
Unknown
Main impact
島田市 announced that unauthorized access was confirmed at the email delivery service's management company, and registered email addresses may have been leaked.
Information involved
Email address
Cause / key point
Unauthorized access confirmed at the management company.About Supply chain attacks (via vendors & shared services)
Industry
Government & municipal
Listing / capital
Government / public body

島田市 (municipality)

Sources
Last updated
October 20, 2026
Email addressHow 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: Supply chain attacks (via vendors & shared services)(Compromising the provider instead of the user)

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