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[Investigating][Severity: Critical][Intrusion]

Sunstage: Belluna Notice breach may expose bank details of 19,853 customers

An intrusion through the application site may have exposed names and bank details of up to 19,853 Belluna Notice customers; the site is suspended.

Disclosed

2026-11-02

Organizations involved

1

Leaked or at risk

19.9K

19,853

Downtime

Unknown

What happened

Sunstage detected unauthorized access through the application site to its member system around 03:20 on 28 October. It stopped both systems that morning. The member system resumed at 20:00 after safety checks, while the application site remained suspended at the 2 November disclosure. [1]

Impact and response

Data linked to up to 19,853 customer IDs may have been exposed, including names, addresses, phone numbers, emails, bank accounts and contract details. The company has not confirmed that every record was viewed or taken. Passwords and identity-document images are excluded. Customer notifications began on 30 October, with reports to police and the Personal Information Protection Commission. [1]

Timeline

  1. Detected 2026-10-28
  2. Disclosed 2026-11-02
  3. 5 days

Services hit

Organizations involved

Sources

  1. [1][Official]ベルーナノーティスのサービス申込サイトへの不正アクセスに関するお詫びとお知らせSunstage · 2026-11-02