RCE in Librenms

CVE-2026-55182

LibreNMS is a network monitoring system. In versions from 21.6.0 up to 26.5.0, the Signal alert transport is vulnerable to command injection because the signal-cli path and the Recipient field of an alert transport entry are insufficiently escaped before being passed to an exec call. An authenticated administrator can craft a transport entry whose Recipient contains shell metacharacters and whose path points to the bundled composer_wrapper.php script, which itself passes attacker-controlled input to further unsafe exec calls. By chaining these calls, the administrator can execute arbitrary operating-system commands on the LibreNMS host. This issue is fixed in version 26.5.0.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

EPSS exploit prediction

EPSS: 0.016 (75.2th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 75.2% 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-2026-55182: held from 0.011 to 0.016.

EPSS over last 30 days · oldest: 0.011 · newest: 0.016 · change: +0.005

Affected products

  • Librenms — versions >= 21.6.0, < 26.5.0

Weakness classification (CWE)

References