XSS in Librenms
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.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (15.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L.
Affected products
- Librenms — versions < 26.2.0
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Third Party Advisory)
- security-advisories@github.com (x_refsource_MISC, Issue Tracking)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-26989?
- CVE-2026-26989 is a medium-severity vulnerability in Librenms, classified under Cross-site Scripting. CVSS score: 4.3/10. Published 2026-02-20.
- How severe is CVE-2026-26989?
- Medium severity. CVSS v3 base score is 4.3 out of 10.