CVE-2026-5131 Server-Side Request Forgery in GREENmod
An attacker can exploit incorrect named pipe permissions to perform Server-Side Request Forgery, potentially executing code or reading data on Windows systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-5131?
CVE-2026-5131 is a medium-severity server-side request forgery vulnerability in Nomios Poland GREENmod, published on 17 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
GREENmod uses named pipes for communication between plugins, the web portal, and the system service, but the access control lists for these pipes are configured incorrectly. This allows an attacker to communicate with the stream and upload any XML or JSON file, which will be processed by the named pipe with the privileges of the user under whose context the service is running. This allows for Server-Side Request Forgery to any Windows system on which the agent is installed and which provides communication via SMB or WebDav.
This issue was fixed in version 2.8.33.
Weakness: CWE-918
Which versions are affected by CVE-2026-5131?
How do I fix CVE-2026-5131?
No fix has been published for CVE-2026-5131 yet. Limit exposure of the affected software until one is available.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2026-5131 being exploited?
There is no known exploitation of CVE-2026-5131 in the wild and no public exploit code.
Sources
Also known as GHSA-f2cg-3cww-mcq8.