What’s Vulnerable › Vulnerabilities

CVE-2026-55182: LibreNMS: Remote Code Execution by Signal Alert Transportation Module

• Severity: high (CVSS 8.6 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-26 · updated 2026-09-09
• Weakness: CWE-77

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.

Affected products

• librenms: from 21.6.0, < 26.5.0

References

• https://github.com/librenms/librenms/commit/868e3b966a
• https://github.com/librenms/librenms/releases/tag/26.5.0
• https://github.com/librenms/librenms/security/advisories/GHSA-c9fv-cgmm-2wg7
• https://github.com/librenms/librenms/security/advisories/GHSA-c9fv-cgmm-2wg7

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