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JAENES
BLeak confirmedSeptember 8, 2026 announced

立教大学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
April 27, 2026
Announced on
September 8, 2026
Severity
BIncidents centered on names and contact details.
Scale
1 people
Main impact
Six email accounts (four students and two alumni) were misused, and a total of 17,668 spam emails were confirmed sent; some of the spam contained information on one faculty member.
Information involved
Email addressFull name
Cause / key point
The cause is under investigation.
Industry
Education
Listing / capital
Non-profit corporation
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: Under investigation / not stated(Cause not disclosed)

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