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JAENES
BLeak confirmedJuly 17, 2026 announced

メディア4uData 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
July 17, 2026
Severity
BIncidents centered on names and contact details.
Scale
22,928 records
Main impact
22,928 records potentially constituting personal information were inspected and confirmed to include contact person names, business email addresses, etc. Passwords and message bodies were excluded.
Information involved
Email addressFull name
Cause / key point
Unauthorized access that used a client account of a specific company as the entry point.
Industry
Media & entertainment
Listing / capital
Unlisted
Sources
Last updated
October 20, 2026
Email 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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