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Fencer Vulns
medium 6.1

CVE-2026-84191 json

LibreNMS before 26.5.0 Stored XSS via SNMP VRF fields

published 2026-09-01 2 mo ago modified 2026-09-08 2 mo ago also EUVD-2026-69028

cvss
6.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 18%
public exploits
0
none known

Summary

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.

Patch / fix

  • librenms librenms 26.5.0

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 18% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
CNA 3.1 6.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • librenms librenms

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.