Vvveb CMS RCE: Authenticated Users Can Own Your Server

The National Vulnerability Database has detailed a critical remote code execution flaw (CVE-2026-6249) in Vvveb CMS version 1.0.8. This vulnerability allows authenticated attackers to execute arbitrary operating system commands. Attackers can bypass the media upload’s extension deny-list by uploading a PHP webshell with a .phtml extension. Once uploaded to the public media directory, these malicious files can be requested via HTTP, leading to full server compromise.

The CVSS score of 8.8 highlights the severity of this flaw. For defenders, this means that any authenticated user on a vulnerable Vvveb CMS instance could potentially gain complete control of the underlying server. This isn’t a zero-click exploit, but it drastically lowers the bar for attackers who already have a foothold or can trick an authenticated user into uploading the shell.