SHINDO3

Osaka Prefectural Senyo High School

Osaka Prefecture

Students in 7 classes257people

LEAK CONFIRMEDFull name / Posts / uploadsMisconfiguration · Closed (final report)

Open in the live monitor ▶
Disclosed
Aug 28, 2026
Leak
Leak confirmed
Type
Misconfiguration
Status
Closed (final report)
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityFull name
Account dataClass and class roll number, Scores
Communications & contentAnswers to quizzes in an English Logic and Expression II course
ContactEmail addresses for personal school devices

How many

  • Students in 7 classes 257 people
  • Students who viewed the sheet 6 people

Who is affected

  • Students

Cause

The teacher in charge had missed the staff meeting that explained how to use the tool, and there was no set way to brief staff who missed it

Timeline

  1. 39 students in the same class could view it
  2. Exposure ended
  3. First disclosure

Response

  • Staff training

Training for all teaching staff; staff who miss a meeting must watch its recording

What you should do

  1. Don't open links in emails from this company. The apology email itself may be fake
  2. Check the company's notice to see if you're affected

Lessons for companies

  1. Two-person review and pre-release tests for sharing and cache changes; monitor cloud config (CSPM)
  2. Report to the PPC: preliminary in 3–5 days, final in 30 (60 if malicious)
  3. Run red teaming and AI-assisted hardening, and publish how much you invest

Sources