CVE-2026-26989

LibreNMS is an auto-discovering PHP/MySQL/SNMP based network monitoring tool. Versions 25.12.0 and below are affected by a Stored Cross-Site Scripting (XSS) vulnerability in the Alert Rules workflow. An attacker with administrative privileges can inject malicious scripts that execute in the browser context of any user who accesses the Alert Rules page. This issue has been fixed in version 26.2.0.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
4.3 MEDIUM
NETWORK
LOW
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L
GitHub_MCNA
4.3 MEDIUM
NETWORK
LOW
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Affected Products (NVD)
VendorProductVersion
librenmslibrenms
𝑥
< 26.2.0
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://github.com/librenms/librenms/commit/087608cf9f851189847cb8e8e5ad002e59170c58
https://github.com/librenms/librenms/pull/19039
https://github.com/librenms/librenms/releases/tag/26.2.0
https://github.com/librenms/librenms/security/advisories/GHSA-6xmx-xr9p-58p7