Vulnerability Description
LibreNMS is an auto-discovering PHP/MySQL/SNMP based network monitoring tool. In versions 26.1.1 and below, the device group name is not sanitized, allowing attackers with admin privileges to perform Stored Cross-Site Scripting (XSS) attacks. When a user adds a device group, an HTTP POST request is sent to the Request-URI "/device-groups". The name of the newly created device group is stored in the value of the name parameter. After the device group is created, the entry is displayed along with relevant buttons such as Rediscover Devices, Edit, and Delete. This issue has been fixed in version 26.2.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Librenms | Librenms | < 26.2.0 |
Related Weaknesses (CWE)
References
- https://github.com/librenms/librenms/commit/64b31da444369213eb4559ec1c304ebfaa0bPatch
- https://github.com/librenms/librenms/pull/19041Issue Tracking
- https://github.com/librenms/librenms/releases/tag/26.2.0ProductRelease Notes
- https://github.com/librenms/librenms/security/advisories/GHSA-5pqf-54qp-32wxExploitThird Party Advisory
FAQ
What is CVE-2026-26991?
CVE-2026-26991 is a vulnerability with a CVSS score of 4.8 (MEDIUM). LibreNMS is an auto-discovering PHP/MySQL/SNMP based network monitoring tool. In versions 26.1.1 and below, the device group name is not sanitized, allowing attackers with admin privileges to perform ...
How severe is CVE-2026-26991?
CVE-2026-26991 has been rated MEDIUM with a CVSS base score of 4.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-26991?
Check the references section above for vendor advisories and patch information. Affected products include: Librenms Librenms.