CVE-2019-25369 OPNsense 19.1 Stored XSS via system_advanced_sysctl.php
Attackers can inject persistent malicious scripts via the tunable parameter in OPNsense, leading to script execution in authenticated user sessions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2019-25369?
CVE-2019-25369 is a medium-severity cross-site scripting vulnerability in OPNsense, published on 15 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
OPNsense 19.1 contains a stored cross-site scripting vulnerability in the system_advanced_sysctl.php endpoint that allows attackers to inject persistent malicious scripts via the tunable parameter. Attackers can submit POST requests with script payloads that are stored and executed in the context of authenticated user sessions when the page is viewed.
Weakness: CWE-79
Which versions are affected by CVE-2019-25369?
It affects 1 product.
Products include Opnsense Opnsense.
How do I fix CVE-2019-25369?
No fix has been published for CVE-2019-25369 yet. Limit exposure of the affected software until one is available.
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-2019-25369 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25369 exists.
Other vulnerabilities in OPNsense
Sources
Also known as GHSA-mh66-gfv9-x2xc.