What’s Vulnerable › Vulnerabilities

CVE-2026-84192: LibreNMS before 26.3.1 Stored XSS via SNMP/Syslog Data

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-01 · updated 2026-10-08
• Weakness: CWE-79

Description

LibreNMS before 26.3.1 contains a stored cross-site scripting vulnerability in legacy PHP templates that output SNMP-sourced and syslog-sourced data without escaping. An attacker who controls a monitored network device can inject arbitrary JavaScript through SNMP interface descriptions or syslog program fields that executes when authenticated users view affected pages.

Affected products

• librenms: before 26.3.1 — fixed in 26.3.1

How to fix

Upgrade to a fixed version: librenms 26.3.1. Check the vendor advisory for mitigations.

References

• https://github.com/librenms/librenms/security/advisories/GHSA-7w8c-qgxg-m7jx
• https://www.vulncheck.com/advisories/librenms-before-26.3.1-stored-xss-via-snmp-syslog-data
• https://github.com/librenms/librenms/security/advisories/GHSA-7w8c-qgxg-m7jx

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