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.

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)

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.

Affected products

Librenms

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (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.