# CVE-2026-73973 — Linuxfabrik monitoring-plugins

> As of 2026-08-19, CVE-2026-73973 is a MEDIUM-severity vulnerability in Linuxfabrik monitoring-plugins, CVSS v3.1 5.5, EPSS 0.2% (12.2th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-73973 as of 2026-08-19; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-08-19

## What is 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.

The record classifies CVE-2026-73973 under weakness classes [CWE-22](https://intel.threadlinqs.com/cwe/CWE-22), [CWE-269](https://intel.threadlinqs.com/cwe/CWE-269). Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 48 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 5.5 — MEDIUM (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **EPSS (FIRST):** 0.2% probability of exploitation in the next 30 days, higher than 12.2% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-18, last modified 2026-08-19

## Is CVE-2026-73973 being exploited?

It currently carries a trending score of 33 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **Linuxfabrik**: monitoring-plugins

## How to fix CVE-2026-73973

No vendor patch reference has been recorded for CVE-2026-73973 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-73973

No threat campaign in the Threadlinqs corpus currently references CVE-2026-73973, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-08-19. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com](https://github.com/Linuxfabrik/monitoring-plugins/security/advisories/GHSA-f54c-p5vg-mr5c)

**Other references**

- [github.com](https://github.com/Linuxfabrik/monitoring-plugins/commit/a0ca1268d84e0caf10442b9c7477d699b52d1c92)
- [github.com (CHANGELOG)](https://github.com/Linuxfabrik/monitoring-plugins/blob/ae486fc629e1ca9373e1b6dd5e395603ee453bbc/CHANGELOG.md#v700---2026-08-14)
- [github.com (v7.0)](https://github.com/Linuxfabrik/monitoring-plugins/releases/tag/v7.0.0)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-73973
Full detection coverage and IOCs for threats exploiting CVE-2026-73973 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp