CVE-2026-63303 Path Traversal in Quick.CMS
An authenticated admin can read files outside the webroot via path traversal in Quick.CMS, though the vendor deems exploitation unlikely.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-63303?
CVE-2026-63303 is a medium-severity path traversal vulnerability in OpenSolution Quick.CMS, published on 28 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
A Path Traversal vulnerability exists in Quick.CMS through the URI path component of HTTP requests, where the server fails to normalize dot-dot-slash (../) sequences before resolving and serving the requested file. An authenticated attacker with admin privileges can use this vulnerability to read contents of files located in the sibling directory of the webroot via a crafted HTTP request containing ../ sequences in the URI.
The vendor assessed the likelihood of exploitation as very low and determined that a fix is not necessary.
Weakness: CWE-23
Which versions are affected by CVE-2026-63303?
How do I fix CVE-2026-63303?
No fix has been published for CVE-2026-63303 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-63303 being exploited?
There is no known exploitation of CVE-2026-63303 in the wild and no public exploit code.
Sources
Also known as GHSA-5wcv-j62r-8fp5.