CVE-2026-4225 CMS Made Simple User Management listusers.php cross site scripting
Remote attackers can inject malicious scripts via the Message argument in the User Management module, potentially compromising user sessions.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-4225?
CVE-2026-4225 is a medium-severity cross-site scripting vulnerability in CMS Made Simple, published on 16 Mar 2026. An attacker needs administrator access to exploit it, and only if a user opens a file or follows a link.
Official description
A security flaw has been discovered in CMS Made Simple up to 2.2.21. Impacted is an unknown function of the file admin/listusers.php of the component User Management Module. Performing a manipulation of the argument Message results in cross site scripting. The attack is possible to be carried out remotely. The exploit has been released to the public and may be used for attacks.
Which versions are affected by CVE-2026-4225?
How do I fix CVE-2026-4225?
No fix has been published for CVE-2026-4225 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-2026-4225 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4225 exists.
Sources
Also known as GHSA-g5vr-q7cx-vw4q.