CVE-2025-65000: Checkmk

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

SSH private keys of the "Remote alert handlers (Linux)" rule were exposed in the rule page's HTML source in Checkmk <= 2.4.0p18 and all versions of Checkmk 2.3.0. This potentially allowed unauthorized triggering of predefined alert handlers on hosts where the handler was deployed.

Affected products

• Checkmk Checkmk: version 2.2.0 only; version 2.3.0 only; version 2.4.0 only

Published 2025-12-18. Last modified 2026-06-17.