What is the CVSS score of CVE-2026-26989?

CVE-2026-26989 has a CVSS 3.1 base score of 4.3 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L. EPSS exploitation probability: 0.0%.

Which versions of SNMP are affected by CVE-2026-26989?

Organizations using LibreNMS should be aware of moderate risk from CVE-2026-26989, a cross-site scripting vulnerability rated CVSS 4.3.. A patch is available.

Is there a public PoC exploit available for CVE-2026-26989?

Yes, a public proof-of-concept exploit is available for CVE-2026-26989. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-26989?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

SNMP CVE-2026-26989

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-02-20 security-advisories@github.com

GHSA-6xmx-xr9p-58p7

XSS SNMP MySQL Librenms

4.3

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

4.3 MEDIUM

AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:04 vuln.today

PoC Detected

Feb 20, 2026 - 16:25 vuln.today

Public exploit code

Patch released

Feb 20, 2026 - 16:25 nvd

Patch available

CVE Published

Feb 20, 2026 - 02:16 nvd

MEDIUM 4.3

DescriptionGitHub Advisory

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.

AnalysisAI

Stored XSS in LibreNMS Alert Rules allows authenticated administrators to inject malicious scripts that execute when other users view the Alert Rules page, affecting versions 25.12.0 and below. Public exploit code exists for this vulnerability, though exploitation requires high-level administrative privileges and user interaction. The vulnerability has been patched in version 26.2.0.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Librenms. 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.

RemediationAI

A vendor patch is available — apply it immediately. Fixed in version 26.2.0.. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.