セガ、セガフェイブData breach / unauthorized access incident
- Occurred on
- July 1, 2026
- Announced on
- November 9, 2026
- Severity
- CLimited data such as email addresses and identifiers.
- Scale
- 2,196,044 records
- Main impact
- It was announced that 2,196,044 email addresses were leaked externally from newsletters sent by セガ and セガフェイブ due to unauthorized access to an email delivery service vendor. Names, addresses, credit card information, and login passwords are said not to have been leaked.
- Information involved
- Email address
- Cause / key point
- Information was leaked because アララ's delivery system, which is entrusted with the email distribution work, was subject to unauthorized access.
- Industry
- Manufacturing
- Listing / capital
- Listed companyParent company (listed holding company): セガサミーホールディングス
セガ is a subsidiary under セガサミーホールディングス.
- Sources
- Last updated
- November 10, 2026
Where to go for this information
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Written & reviewed
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: Unauthorized access (method undisclosed)(Breached, but the technique was not identified or disclosed)
Read the Unauthorized access (method undisclosed) guide and national trends →