CVE-2026-4239 Lagom WHMCS Template Datatables prototype pollution
Remote attackers can exploit prototype pollution in the Datatables component of the Lagom WHMCS Template to potentially execute code or escalate privileges.
- 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-2026-4239?
CVE-2026-4239 is a medium-severity code injection vulnerability in Lagom WHMCS Template, published on 16 Mar 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
A vulnerability was found in Lagom WHMCS Template up to 2.3.7. Impacted is an unknown function of the component Datatables. The manipulation results in improperly controlled modification of object prototype attributes. It is possible to launch the attack remotely. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-4239?
How do I fix CVE-2026-4239?
No fix has been published for CVE-2026-4239 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-2026-4239 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4239 exists.
Sources
Also known as GHSA-qw4c-qf3v-3xpp.