CVE-2026-100522 Cotonti through 1.0.0 Reflected XSS via message.php lng parameter
Unauthenticated attackers can execute arbitrary JavaScript in victim browsers via a reflected XSS vulnerability in the message.php lng parameter.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-100522?
CVE-2026-100522 is a medium-severity cross-site scripting vulnerability in Cotonti, published on 26 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Cotonti through 1.0.0 contains a reflected cross-site scripting vulnerability in message.php where the lng parameter is not properly escaped before output in the confirmation dialog. Unauthenticated attackers can craft malicious links with script payloads in the lng parameter to execute arbitrary JavaScript in victim browser sessions.
Weakness: CWE-79
Which versions are affected by CVE-2026-100522?
How do I fix CVE-2026-100522?
No fix has been published for CVE-2026-100522 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-2026-100522 being exploited?
There is no known exploitation of CVE-2026-100522 in the wild and no public exploit code.
Sources
Also known as GHSA-6r43-xr6w-qprx.