shueisha-hapicomi-2026 · Disclosed 2026-09-28
集英社: unauthorized access and impact
Shueisha attributes the incident to attacks on API credentials arising from CMS misconfiguration, privileged-account creation, and repeated API requests. Affected scopes include 2,835 bloggers, 630 projects, 11,237 sent emails, and 10,780 vendor entries.
Outcome: Confirmed breach
Entry path and evidence
- Assessment
Shueisha attributes the incident to attacks on API credentials arising from CMS misconfiguration, privileged-account creation, and repeated API requests.
[s1]p.1 §1 / p.2 §2-4 - Reported fact
Affected scopes include 2,835 bloggers, 630 projects, 11,237 sent emails, and 10,780 vendor entries.
[s1]p.1 §1 / p.2 §2-4
Timeline
Reported response
- Reported fact
Unauthorized accounts were removed, settings changed, and external investigation and notifications undertaken.
[s1]p.1 §1 / p.2 §2-4
Evidence relevant to prevention
Operational controls to inspect
Inspect the disclosed configuration, authorization or operational issue. Verify applicability and retain evidence of behavior after remediation.
Editorial assessment; not a determination of liability. [s1]
Unknowns and AI involvement
The reviewed disclosures do not establish attacker use of AI.
The cause is the organization's assessment; detailed configuration and independent validation are undisclosed.
Sources
[s1] 集英社 · Primary source
集英社：事故に関する公表資料 ↗Reviewed 2026-10-09