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.
History

Wed, 26 Aug 2026 23:45:00 +0000

Type Values Removed Values Added
First Time appeared Librenms
Librenms librenms
Vendors & Products Librenms
Librenms librenms

Wed, 26 Aug 2026 22:00:00 +0000

Type Values Removed Values Added
Description 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.
Title LibreNMS: Remote Code Execution by Signal Alert Transportation Module
Weaknesses CWE-77
References
Metrics cvssV4_0

{'score': 8.6, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-26T21:50:04.014Z

Reserved: 2026-06-16T15:20:43.086Z

Link: CVE-2026-55182

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-26T22:16:24.950

Modified: 2026-08-26T22:16:24.950

Link: CVE-2026-55182

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-26T23:45:03Z