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Japan Network Security Association (JNSA)
Tokyo, Japan3 sources
Confirmed:Confirmed by the organisation, a regulator or a securities filing. First reported 6 Nov 2026.
JNSA security check service hit by unauthorized access
JNSA announced that its Information Security Comprehension Check Service suffered unauthorized access, with up to 15,128 user records potentially leaked including administrator names, company names, email addresses, user IDs and hashed passwords. The association confirmed the access on 4 November and suspended the service.
- Type
- Data breach
- Sector
- Nonprofit
- Records
- 15.1K records confirmed
- First reported
- 6 Nov 2026
- Latest source
- 8 Nov 2026
What to do
- If you have an account, change that password, and anywhere you reused it.
- Turn on two-factor authentication, ideally an authenticator app or passkey, not SMS.
- Expect phishing that uses your real details. Do not click links in messages about this incident; go to the company's site directly.
- If payment cards were involved, watch statements and ask your bank for a new card.
- If government ID or social security numbers were involved, consider a credit freeze.
- If this is a vendor of yours, ask what of your data they held and whether it was in scope.
- Reset any API keys, SSO trusts or shared credentials you have with them.
- Brief your help desk: attackers often impersonate the breached brand next.
Not sure? Ask an assistant with the sources attached, or have a coding agent check your systems.
Check your systems for Japan Network Security Association (JNSA)
Sources
3- qiita.com8 Nov 2026qiita.com/pitopito/items/9f611ca58a041d26d75d
- legalagent.co.jp8 Nov 2026legalagent.co.jp/legal-lab/security-incidents
- finance.biggo.com6 Nov 2026finance.biggo.com/news/0679445c-3184-412c-8bb0-183b90ff2a14
Confidence 90% that this is real and correctly placed. Locations are city centroids at best. Spotted an error? Report a correction.