CVE-2026-105123 W (wcms) through 3.18.0 RCE and Arbitrary File Write via Media Upload API
Authenticated editors can achieve remote code execution and arbitrary file modification in W CMS by uploading malicious PHP files via the media upload API.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-105123?
CVE-2026-105123 is a high-severity vulnerability in vincent-peugnet wcms, published on 3 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
W (vincent-peugnet/wcms) through 3.18.0 contains a remote code execution vulnerability that allows authenticated editors to write arbitrary files by abusing the unvalidated path in POST /api/v0/media/upload/[*:path]. Attackers can upload .php files executed by the web server, use encoded ../ sequences to write outside the media directory, and delete arbitrary files via DELETE /api/v0/media/[*:path].
Weakness: CWE-434
Which versions are affected by CVE-2026-105123?
How do I fix CVE-2026-105123?
No fix has been published for CVE-2026-105123 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-105123 being exploited?
There is no known exploitation of CVE-2026-105123 in the wild and no public exploit code.
Sources
Also known as GHSA-r3hg-hgx7-58g9.