CVE-2026-108566 InstantSoft icms2 Private Message index.tpl.php index cross site scripting
Remote attackers can inject malicious scripts via the nickname field in the Private Message Handler, potentially leading to session hijacking or code execution.
- 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-2026-108566?
CVE-2026-108566 is a medium-severity cross-site scripting vulnerability in InstantSoft icms2, published on 11 Oct 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 has been found in InstantSoft icms2 up to 2.18.2. This issue affects the function index of the file templates/default/controllers/messages/index.tpl.php of the component Private Message Handler. Such manipulation of the argument nickname leads to cross site scripting. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The name of the patch is 3a1ec8fcb073a46d06a2ab83bc2bf68225834281. It is best practice to apply a patch to resolve this issue.
Which versions are affected by CVE-2026-108566?
How do I fix CVE-2026-108566?
No fix has been published for CVE-2026-108566 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-2026-108566 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-108566 exists.
Sources
Also known as GHSA-j944-2cmv-5vxf.