CVE-2026-55182

8.6 HIGH 2% exploit odds Fix listed Injection Web app

What it is

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.

At a glance

Exploitability: Can be exploited over the network with an admin-level account. High risk of data exposure, data tampering, service disruption.
Exploit odds: 1.6% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-08-26 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-09 21:09 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 1.6% in the next 30 days (EPSS).
Severity: 8.6 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-08-26 22:16 UTC
Last modified: 2026-09-09 21:09 UTC
Exploit probability: 1.6% · EPSS, next 30 days
Weakness: CWE-77 · Command injection
Record status: Deferred

Attack profile CVSS 4.0 · 8.6

Attack vector: Network
Complexity: Low
Attack requirements: None
Privileges needed: High
User interaction: None
Confidentiality: High
Integrity: High
Availability: High

Raw 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-55182.md and follow it. Check whether this project is affected by CVE-2026-55182. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

· More options · Status badge

Download Square Reddit

Fix and advisories

References

NVD record · CVE.org record