Librenms
CVE-2026-26989
MEDIUM
GHSA-6xmx-xr9p-58p7
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK
2 techniques across 2 tactics: Initial Access, Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS 4.3 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: High. User interaction: Required. Exploitation requires authentication. Exploitable via remote/network. Public exploit/POC available. |
| Exploit ScenarioDerived | A remote attacker (requires authentication) could exploit this vulnerability to compromise the affected system. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAIv1 – Mar 12, 2026
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.
Earlier versions of this analysis (1)
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. [CVSS 4.3 MEDIUM]
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.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in composer
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
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.
Know when Librenms gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
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
Lifecycle Timeline
3DescriptionGitHub 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.
Executive ViewAI
Organizations using LibreNMS should be aware of moderate risk from CVE-2026-26989, a cross-site scripting vulnerability rated CVSS 4.3. Attackers could inject scripts to steal sessions or perform actions as authenticated users. Proof-of-concept code is publicly available. A patch is available and should be applied during regular vulnerability management.
Apply vendor patch. If patching is delayed: implement CSP headers, enable HttpOnly cookies, deploy WAF XSS rules.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.
Affected Products (CPE)GitHub Advisory
An issue was discovered in LibreNMS through 1.47. Rated high severity (CVSS 7.2), this vulnerability is remotely exploit
Librenms 21.11.0 is affected by a path manipulation vulnerability in includes/html/pages/device/showconfig.inc.php. Rate
An issue was discovered in LibreNMS through 1.47. Rated critical severity (CVSS 9.8), this vulnerability is remotely exp
Authentication bypass in the LibreNMS REST API (all versions before 26.8.0) lets unauthenticated remote attackers reach
SQL injection in LibreNMS 25.12.0 and below. PoC and patch available.
An issue was discovered in LibreNMS through 1.47. Rated critical severity (CVSS 9.1), this vulnerability is remotely exp
SQL injection in LibreNMS versions 25.12.0 and below allows authenticated users to extract sensitive database informatio
LibreNMS is an open-source, PHP/MySQL/SNMP-based network monitoring system. Rated high severity (CVSS 8.8), this vulnera
An issue was discovered in LibreNMS before 1.65.1. Rated high severity (CVSS 8.8), this vulnerability is remotely exploi
An issue was discovered in LibreNMS 1.50.1. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable,
An issue was discovered in LibreNMS through 1.47. Rated high severity (CVSS 8.8), this vulnerability is remotely exploit
Command injection in LibreNMS's Virtualization Discovery module enables authenticated administrator-level users to execu
Exploit-DB