XSS in Librenms
CVE-2026-84191
LibreNMS before 26.5.0 contains stored cross-site scripting vulnerabilities in VRF display pages where mplsVpnVrfDescription, vrf_name, and mplsVpnVrfRouteDistinguisher fields from SNMP polling are rendered without sanitization. Attackers controlling a monitored network device can inject arbitrary JavaScript through SNMP responses that executes in the browser of any user viewing VRF-related pages.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.003 (16.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 17th percentile — 16.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/librenms/librenms/security/advisories/GHSA-g993-wffj-m3gv (vendor-advisory)
- www.vulncheck.com/advisories/librenms-before-26.5.0-stored-xss-via-snmp-vrf-fie… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-84191?
- CVE-2026-84191 is a medium-severity vulnerability in Librenms, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2026-09-01.
- How severe is CVE-2026-84191?
- Medium severity. CVSS v3 base score is 6.1 out of 10.