Ymirlink security incident history
Hacking, data breaches and other security incidents involving Ymirlink, with related coverage.
Nearly 47.86 million recipient records leaked from 49 Ymirlink email systems
47.9MImpact: 47,864,147 recipient records across 49 systems, including duplicate entries; approximately 420,000 unencrypted passwords also leaked
Forty-nine customer-specific systems for Japanese company Ymirlink's Cuenote FC email delivery service were compromised. Investigation results released on November 11, 2026, confirmed that 47,864,147 recipient records were leaked, a total that includes duplicates rather than a count of unique victims. Attackers were found to have installed malware through vulnerabilities and abused the legitimate CSV export feature after hijacking login sessions, while personal information held by some customers and approximately 420,000 unencrypted passwords from a discontinued service were also leaked.
Related reports: 5 · last report →