CVE-2026-55426

Name of the Vulnerable Software and Affected Versions linuxfabrik-lib versions prior to 5.0.0 Linuxfabrik Monitoring Plugins versions prior to 5.2.0

Description A local privilege escalation issue exists when a check plugin includes user-provided input within a command passed to the shell exec() function. An attacker controlling the nagios user can exploit this to execute arbitrary commands, potentially gaining root privileges if the plugin is listed in the sudoers file. For instance, in the restic-check plugin, the --repo variable is passed to shell exec(), which splits commands at the | boundary and executes them separately, allowing for command injection.

Recommendations Update linuxfabrik-lib to version 5.0.0 or later. Update Linuxfabrik Monitoring Plugins to version 5.2.0 or later. As a temporary mitigation, restrict the use of the --repo parameter in the restic-check plugin to prevent unauthorized command execution.