SHINDO5

LINE GAME

LY Corporation

Unique users~6.1Mpeople

LEAK CONFIRMEDMember / user IDMisconfiguration · Contained

Open in the live monitor ▶
Disclosed
Jul 13, 2026
Leak
Leak confirmed
Type
Misconfiguration
Status
Contained
Security spend
Measures, no amount
Compensation
Not announced

What leaked

Account dataInternal identifiers

Not leaked

  • Users' names, addresses, phone numbers, bank accounts and credit card numbers are not included

How many

  • Unique users ~6.1M people
  • Of which in Japan ~5.7M people

Who is affected

  • LINE GAME users

Cause

Because settings were not adequately checked when a tool's configuration was changed, internal identifiers were sent from users' devices to a tool provided by an outside company

Timeline

  1. Transmission began
  2. Stopped on April 2-3, 2026 for games still in service (June 11, 2025 for a service already closed)
  3. First disclosure
  4. Administrative guidance from the Ministry of Internal Affairs and Communications

Response

  • Service stopped
  • Data deleted
  • Governance / committee

Transmission has stopped and the tool provider deleted the data. Recurrence prevention through stronger management of specified user information, and strict legal compliance

What you should do

  1. Check the company's notice to see if you're affected

Lessons for companies

  1. Two-person review and pre-release tests for sharing and cache changes; monitor cloud config (CSPM)
  2. Never sit on a known defect. Test every change before production
  3. Report to the PPC: preliminary in 3–5 days, final in 30 (60 if malicious)
  4. Run red teaming and AI-assisted hardening, and publish how much you invest

Sources