This vulnerability (CVE-2025-39666) involves an untrusted search path (CWE-426) in Checkmk software that allows a local site user to escalate privileges to root by manipulating files processed during execution of the `omd` administrative command run as root. Affected versions include Checkmk 2.2.0 (EOL), 2.3.0 before 2.3.0p46, 2.4.0 before 2.4.0p25, and 2.5.0 beta before 2.5.0b3. The CVSS 4.0 vector indicates local attack vector, low attack complexity, no user interaction, and high impact on confidentiality, integrity, availability, and scope. No patch or official remediation guidance is currently available in the vendor data.

Successful exploitation allows a local site user to escalate privileges to root, potentially compromising the entire system. This can lead to full system control, unauthorized access to sensitive data, and disruption of services. The vulnerability affects multiple versions of Checkmk, including some that are end-of-life.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict local user access to the Checkmk site context and avoid running the `omd` administrative command in environments where untrusted users have file manipulation capabilities. Monitor vendor channels for updates and apply patches promptly once available.