CVE-2026-73973 Path traversal in monitoring-plugins
Attackers with monitoring account access can read arbitrary root files like /etc/shadow via path traversal in the logfile plugin, leading to privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-73973?
CVE-2026-73973 is a medium-severity path traversal vulnerability in Linuxfabrik monitoring-plugins, published on 18 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Linuxfabrik Monitoring Plugins provides monitoring plugins for Icinga, Nagios, and related systems. Prior to version 7.0.0, check-plugins/logfile/logfile accepted a free-form --filename path and opened it as root when invoked through the shipped nagios or icinga sudoers allowlist, without confining the resolved path to /var/log. An attacker who controls the monitoring account can select a root-readable file such as /etc/shadow and use --warning-regex . while leaving SUPPRESS_OUTPUT false, causing each nonempty line to be collected in warn_matches and returned through lib.base.oao(). The vulnerable flow passes the expanded scan_path directly to open(), and neither real-path containment nor an allowlist protects the sink. The same fix also confines mysql-logfile and openvpn-client-list paths, allows only documented log roots, and resolves symlinks and parent-directory traversal before checking containment. This issue is fixed in version 7.0.0.
Which versions are affected by CVE-2026-73973?
How do I fix CVE-2026-73973?
No fix has been published for CVE-2026-73973 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-73973 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-73973 exists.
Sources
Also known as GHSA-f54c-p5vg-mr5c.