CVE-2026-14449 POST-based reflected XSS via the thanks parameter in form components
Attackers can execute arbitrary scripts in victim browsers via the thanks parameter in u5CMS form components, potentially leading to session hijacking.
- 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-2026-14449?
CVE-2026-14449 is a medium-severity cross-site scripting vulnerability in u5CMS, published on 2 Jul 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
u5CMS through v12.8.8 is vulnerable to reflected XSS via the ‘thanks’ parameter in multiple form components
Weakness: CWE-79
Which versions are affected by CVE-2026-14449?
How do I fix CVE-2026-14449?
No fix has been published for CVE-2026-14449 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-2026-14449 being exploited?
There is no known exploitation of CVE-2026-14449 in the wild and no public exploit code.
Sources
Also known as GHSA-5vjc-525r-rgvh.