CVE-2025-52374: Hmailserver

Medium severity, CVSS 4.6. EPSS: 0.2% chance of exploitation in the next 30 days.

Use of hardcoded cryptographic key in Encryption.cs in hMailServer 5.8.6 and 5.6.9-beta allows attacker to decrypt passwords to other servers from hMailAdmin.exe.config file to access other hMailServer admin consoles with configured connections.

Affected products

• Hmailserver Hmailserver: version 5.6.9 only; version 5.8.6 only

Published 2025-07-21. Last modified 2026-06-17.