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CVE-2026-26991

LibreNMS vulnerable to Stored Cross-site Scripting through unsanitized /device-groups name

Published: Feb 20, 2026Updated: Feb 20, 2026 Sources: CVE List NVD GHSACWE-79
NVD MITRE
4.8CVSSMEDIUM
EPSS Score
0.2%
Top 88.2%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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 Vector Breakdown

AV:NAC:LPR:HUI:RS:CC:LI:LA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:HPrivileges Required
High
UI:RUser Interaction
Required
Scope
S:CScope
Changed
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:NAvailability
None
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Weaknesses

CWE-79

Affected Products

librenmslibrenms
On-prem
Enterprise Software / itsm-monitoring
librenms/librenmsPackagistOSS Libraries
librenmsoss-projectEnterprise Softwareaka librenms/librenms, librenms
packagistpackage-ecosystemOSS Libraries

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available

MITRE ATT&CK

2 techniques
Execution
Initial Access
View detailed technique mapping

References

https://github.com/librenms/librenms/commit/64b31da444369213eb4559ec1c304ebfaa0ba12c
github.com
https://github.com/librenms/librenms/pull/19041
github.com
https://github.com/librenms/librenms/releases/tag/26.2.0
github.com
and 3 more references View all →

Timeline

Published
Feb 20, 2026
Last Updated
Feb 20, 2026

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