LibreNMS up to 26.1.x HTTP POST Request /device-groups cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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4.1$0-$5k0.00

Summaryinfo

A vulnerability was found in LibreNMS up to 26.1.x and classified as problematic. This vulnerability affects unknown code of the file /device-groups of the component HTTP POST Request Handler. The manipulation results in cross site scripting. This vulnerability is cataloged as CVE-2026-26991. The attack may be launched remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in LibreNMS up to 26.1.x. It has been classified as problematic. Affected is an unknown code of the file /device-groups of the component HTTP POST Request Handler. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-26991 since 02/17/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 26.2.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 64b31da444369213eb4559ec1c304ebfaa0ba12c is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 4.1
VulDB Meta Temp Score: 4.1

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 4.8
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: LibreNMS 26.2.0
Patch: 64b31da444369213eb4559ec1c304ebfaa0ba12c

Timelineinfo

02/17/2026 CVE reserved
02/20/2026 +3 days Advisory disclosed
02/20/2026 +0 days VulDB entry created
02/22/2026 +2 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-5pqf-54qp-32wx
Status: Confirmed

CVE: CVE-2026-26991 (🔒)
GCVE (CVE): GCVE-0-2026-26991
GCVE (VulDB): GCVE-100-347064

Entryinfo

Created: 02/20/2026 07:58
Updated: 02/22/2026 07:44
Changes: 02/20/2026 07:58 (71), 02/22/2026 07:44 (12)
Complete: 🔍
Cache ID: 216::103

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