Vulnerability · Published Feb 20, 2026 · Assigned by GitHub_M
CVE-2026-26991LibreNMS vulnerable to Stored Cross-site Scripting through unsanitized /device-groups name
Medium 5.1
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 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | librenms/librenms | 26.2.0 | GHSA-5pqf-54qp-32wx |
Affected products (as reported)
Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
References
- https://github.com/librenms/librenms/security/advisories/GHSA-5pqf-54qp-32wx x_refsource_CONFIRM
- https://github.com/librenms/librenms/pull/19041 x_refsource_MISC
- https://github.com/librenms/librenms/commit/64b31da444369213eb4559ec1c304ebfaa0ba12c x_refsource_MISC
- https://github.com/librenms/librenms/releases/tag/26.2.0 x_refsource_MISC