Stored Cross-Site Scripting in LibreNMS by The LibreNMS Community
CVE-2026-84191

5.3MEDIUM

Key Information:

Vendor

Librenms

Status
Librenms
Vendor
CVE Published:
1 September 2026

What is CVE-2026-84191?

LibreNMS versions prior to 26.5.0 are susceptible to stored cross-site scripting vulnerabilities. These vulnerabilities exist in the VRF display pages, where fields such as mplsVpnVrfDescription, vrf_name, and mplsVpnVrfRouteDistinguisher are exposed to SNMP polling data without proper sanitization. An attacker could exploit this flaw by injecting malicious JavaScript through manipulated SNMP responses, which would execute in the browsers of users accessing VRF-related pages. This compromise can lead to unauthorized actions and data exposure, making it essential for users to upgrade to the latest version to mitigate the risk.

Affected Version(s)

librenms 0 < 26.5.0

librenms 26.5.0

References

https://github.com/librenms/librenms/security/advisories/...
vendor-advisory
https://www.vulncheck.com/advisories/librenms-before-26.5...
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

romain-deperne
.