mediaplex-2026 · Disclosed 2026-07-03
テレビ朝日メディアプレックス: unauthorized access and impact
Investigators report possible theft and abuse of authentication-federation account credentials. 1,343 employee, 2,786 applicant and 414 contact records leaked or may have leaked.
Outcome: Confirmed breach
Entry path and evidence
Timeline
Disclosure date established by the reviewed notice. [s1]
Reported response
- Reported fact
Affected servers and external connections were stopped; monitoring and controls were reviewed after forensics.
[s1]第2報 pp.1-3 §§1-5
Cause and mitigation hypotheses
Not assessed. Editorial hypotheses have not been added for this incident; this does not establish safety or a confirmed cause.
Evidence relevant to prevention
Insufficient evidence
Undisclosed entry or patch timing prevents an avoidability assessment. Inspect privileges, retrieval logs, retention and deployed configuration using the linked rules.
Editorial assessment; not a determination of liability. [s1]
Unknowns and AI involvement
The reviewed disclosures do not establish attacker use of AI.
The authentication sequence is described as likely; the full entry chain and confirmed extraction scope are unresolved.
Sources
[s1] テレビ朝日メディアプレックス · Primary source
テレビ朝日メディアプレックス：事故に関する公表資料 ↗Reviewed 2026-10-09