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JAENES
CPossible leakOctober 27, 2026 announced

バンダイナムコ（THE GUNDAM BASE MEMBERS・バンダイナムコID、メール配信委託先: ユミルリンク）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
October 16, 2026
Announced on
October 27, 2026
Severity
CLimited data such as email addresses and identifiers.
Scale
346,247 records
Main impact
Due to unauthorized access to the mail delivery contractor ユミルリンク's system, it was announced that 346,247 records such as THE GUNDAM BASE MEMBERS members' email addresses may have been leaked. The affected data are email addresses and internal identifiers for バンダイナムコID management and do not include names, addresses, purchase histories, login passwords, or credit card information; the affected mail service has been suspended, official notification e-mails will not include URLs, and members are warned about phishing; across the contractor ユミルリンク as a whole, data output from 49 systems of the delivery system 「Cuenote FC」 totalling over 50,000,000 records has been confirmed.
Information involved
Email addressUser / member ID
Cause / key point
Unauthorized access to the mail delivery contractor ユミルリンク's system (exploitation of vulnerabilities in libraries, etc., and acquisition of authentication credentials of support and quality-management personnel); the contractor detected the incident on 2026-10-16, and a second report on the 26th disclosed an expanded list of affected systems and record counts.About Targeted email & phishing
Industry
Media & entertainment
Listing / capital
Listed companyTSE Prime 7832(バンダイナムコホールディングス)

The incident主体 is バンダイナムコグループ (バンダイナムコエンターテインメント・BANDAI SPIRITS), and the listed holding company is バンダイナムコホールディングス (東証プライム・7832).

Sources
Last updated
October 29, 2026

Stock price reaction to the disclosureバンダイナムコホールディングス / 東証プライム 7832

2026.10.07 〜 2026.10.30Loading…

Stock information is reference data based on Yahoo Finance and may be delayed. This site does not solicit or advise investment and does not guarantee the accuracy or completeness of this information. We accept no liability for any investment decision based on it.

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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: Targeted email & phishing(Fake emails and sites that steal credentials)

Read the Targeted email & phishing guide and national trends →

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