Affected: TYPO3 Extension "Content Element Selector"

The extension passes an attacker-controlled cookie directly to PHP's unserialize() without safely processing the input. A remote, unauthenticated attacker can supply a crafted serialized payload to trigger PHP Object Injection, leading to Remote Code Execution on the TYPO3 server. Exploitation requires the content element to be configured with "Persistent Mode: Static" in the plugin settings.