CVE-2026-49131 OPNsense < 26.1.9 Stored XSS via Firewall Rule Description Field
Authenticated attackers can inject scripts into firewall rule descriptions, leading to session hijacking or credential theft for other users.
- 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-2026-49131?
CVE-2026-49131 is a medium-severity cross-site scripting vulnerability in Deciso B.V. OPNsense, published on 3 Aug 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 before 26.1.9 contains a stored cross-site scripting vulnerability that allows authenticated attackers with firewall rule management privileges to inject arbitrary HTML or JavaScript by embedding payloads in the firewall rule description field via the filter API endpoint. The unsanitized description value is persisted and later rendered through the default cell formatter in opnsense_bootgrid.js, which assigns raw cell content to innerHTML, causing injected scripts to execute in the browser of any authenticated user who views the Firewall Rules page, enabling session hijacking or credential theft.
Weakness: CWE-79
Which versions are affected by CVE-2026-49131?
How do I fix CVE-2026-49131?
No fix has been published for CVE-2026-49131 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-2026-49131 being exploited?
There is no known exploitation of CVE-2026-49131 in the wild and no public exploit code.
Sources
Also known as GHSA-2wfc-8j3p-p6cp.