VDB-347066 · CVE-2026-26989 · GHSA-6xmx-xr9p-58p7

LibreNMS up to 26.1.x Alert Rules Page cross site scripting

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
3.8	$0-$5k	0.00

Summaryinfo

A vulnerability was found in LibreNMS up to 26.1.x. It has been declared as problematic. Impacted is an unknown function of the component Alert Rules Page. Such manipulation leads to cross site scripting. This vulnerability is documented as CVE-2026-26989. The attack can be executed remotely. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in LibreNMS up to 26.1.x. It has been rated as problematic. Affected by this issue is some unknown processing of the component Alert Rules Page. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to 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. Impacted is integrity. CVE summarizes:

LibreNMS is an auto-discovering PHP/MySQL/SNMP based network monitoring tool. Versions 25.12.0 and below are affected by a Stored Cross-Site Scripting (XSS) vulnerability in the Alert Rules workflow. An attacker with administrative privileges can inject malicious scripts that execute in the browser context of any user who accesses the Alert Rules page. This issue has been fixed in version 26.2.0.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-26989 since 02/17/2026. The exploitation is known to be easy. The attack may be launched remotely. The exploitation needs additional levels of successful authentication. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1059.007 by the MITRE ATT&CK project.

Upgrading to version 26.2.0 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 087608cf9f851189847cb8e8e5ad002e59170c58 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.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Name

LibreNMS

Version

License

open-source

Website

Product: https://github.com/librenms/librenms/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.8
VulDB Meta Temp Score: 3.8

VulDB Base Score: 2.4
VulDB Temp Score: 2.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 4.8
NVD Vector: 🔒

CNA Base Score: 4.3
CNA Vector (GitHub_M): 🔒

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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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: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: LibreNMS 26.2.0
Patch: 087608cf9f851189847cb8e8e5ad002e59170c58

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-6xmx-xr9p-58p7
Status: Confirmed

CVE: CVE-2026-26989 (🔒)
GCVE (CVE): GCVE-0-2026-26989
GCVE (VulDB): GCVE-100-347066

Entryinfo

Created: 02/20/2026 07:58
Updated: 02/22/2026 07:44
Changes: 02/20/2026 07:58 (67), 02/22/2026 07:44 (11)
Complete: 🔍
Cache ID: 216::103