CVE-2026-84192 LibreNMS before 26.3.1 Stored XSS via SNMP/Syslog Data
An attacker controlling a monitored device can inject JavaScript via SNMP or syslog data, leading to script execution in the web interface for authenticated users.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-84192?
CVE-2026-84192 is a high-severity cross-site scripting vulnerability in librenms, published on 1 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-84192?
2 open source packages ship an affected version, including librenms/librenms.
| Package | Affected | Fixed in |
|---|---|---|
librenms/librenms Packagist | All versions | 26.5.0 |
librenms/librenms Packagist | All versions | 26.5.0 |
How do I fix CVE-2026-84192?
Upgrade librenms/librenms to 26.5.0 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-84192 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-84192 exists.
Sources
Also known as GHSA-7w8c-qgxg-m7jx, GHSA-r97f-5q78-rq8c.