Privilege escalation in Linuxfabrik Monitoring-Plugins

CVE-2026-73973

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 19th percentile — 19.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-73973: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-73973?
CVE-2026-73973 is a medium-severity vulnerability in Linuxfabrik Monitoring-Plugins, classified under Path Traversal. CVSS score: 5.5/10. Published 2026-08-18.
How severe is CVE-2026-73973?
Medium severity. CVSS v3 base score is 5.5 out of 10.