istyle (@cosme email list) data breach

istyle (@cosme email list) announced a data breach on Nov 9, 2026 affecting about 2.8 million email addresses, exposing email addresses and names. It is the second of 2 istyle (@cosme email list) breaches recorded on Teollimi. It happened through a vendor (Ymir Link (Cuenote FC email delivery system)). No settlement or compensation has been announced.

What happened

In a second notice on November 9, 2026, istyle (@cosme) said a break-in at Ymir Link's Cuenote FC email delivery system leaked email addresses of about 2.8 million people it had sent mail to since about 5 a.m. on October 14, 2026, including business partners. Address books stored in the system as of October 16 also leaked for about 8,000 people, some with names and, for business contacts, company and department. No card data was held in the system. This is separate from the @cosme member breach istyle disclosed on November 2.

What should I do?

1. Be wary of emails that pretend to be from @cosme, istyle or Ymir Link, and don't open links or attachments in unexpected messages.
2. istyle says it never emails asking for passwords or card numbers; ignore any that do.
3. Expect more spam at the affected address and report phishing to your email provider.

Other istyle (@cosme email list) breaches: Nov 2, 2026

More data breaches in Japan →

Check the other services you use →