CVE-2026-26991

MEDIUM EPSS 12.0%
Published Feb 20, 20264mo ago · Modified Jun 17, 20262w ago
5.1 CVSS 4.0
Medium
Find Similar
Published Feb 20, 2026 4mo ago
Last Modified Jun 17, 2026 2w ago

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 Details

Base Score
5.1
Exploitability
—
Impact
—
Vector string
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/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
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction P
Scope X

Threat Intelligence

EPSS Exploit Probability
12.0% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

Affected Products 1

VendorProductVersionRange
librenmslibrenms* <26.2.0

References 4

  • github.com https://github.com/librenms/librenms/commit/64b31da444369213eb4559ec1c304ebfaa0ba12c
    Patch
  • github.com https://github.com/librenms/librenms/pull/19041
    Issue Tracking
  • github.com https://github.com/librenms/librenms/releases/tag/26.2.0
    ProductRelease Notes
  • github.com https://github.com/librenms/librenms/security/advisories/GHSA-5pqf-54qp-32wx
    ExploitThird Party Advisory

Remediation

  • github.com https://github.com/librenms/librenms/commit/64b31da444369213eb4559ec1c304ebfaa0ba12c
    Patch