Vulnerability · Published Sep 1, 2026 · Assigned by VulnCheck

CVE-2026-84191LibreNMS before 26.5.0 Stored XSS via SNMP VRF fields

Medium 6.1

In plain English

A medium-severity cross-site scripting in librenms from librenms. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities).

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.3%top 81.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
librenms	librenms	0 – before 26.5.0

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References

GitHub Security Advisory (GHSA-g993-wffj-m3gv) vendor-advisory
VulnCheck Advisory: LibreNMS before 26.5.0 Stored XSS via SNMP VRF fields third-party-advisory