CVE-2026-103540 formtools.org Form Tools Client Settings Clients.class.php updateClientSettingsTab special elements in template engine
Remote attackers can execute arbitrary code via template injection in Form Tools client settings, requiring authentication.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-103540?
CVE-2026-103540 is a medium-severity code injection vulnerability in formtools.org Form Tools, published on 1 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A security vulnerability has been detected in formtools.org Form Tools up to 3.1.1. This vulnerability affects the function Clients::updateClientSettingsTab of the file global/code/Clients.class.php of the component Client Settings. The manipulation of the argument page_titles leads to improper neutralization of special elements used in a template engine. It is possible to initiate the attack remotely. The exploit has been disclosed publicly and may be used. The project was informed of the problem early through an issue report but has not responded yet.
Which versions are affected by CVE-2026-103540?
How do I fix CVE-2026-103540?
No fix has been published for CVE-2026-103540 yet. Limit exposure of the affected software until one is available.
Upgrade, and never evaluate templates, expressions or code built from user input. More about Code injection.
Is CVE-2026-103540 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-103540 exists.
Sources
Also known as GHSA-r99g-f87j-9mpc.