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JAENES
ALeak confirmedJune 26, 2026 announced

宮城県石巻高等学校（採点済み答案）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
June 24, 2026
Announced on
June 26, 2026
Severity
AFinancial and HR records — information that easily translates into monetary damage.
Scale
182 people
Main impact
A teacher mistakenly uploaded PDFs of graded answer sheets to the groupware, and answer sheets for 182 students were viewed. This incident was caused by improper handling of personal information.
Information involved
Not specified in the disclosure
Cause / key point
Graded answer sheets were made public due to a teacher's mistaken posting.
Industry
Education
Listing / capital
Government / public body

Prefectural high school

Sources
Last updated
October 20, 2026
How 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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