CVE-2026-6403: Quick Playground <= 1.3.3 - Unauthenticated Path Traversal to Arbitrary File Read via 'stylesheet' Parameter

The Quick Playground plugin for WordPress is vulnerable to Path Traversal in versions up to and including 1.3.3. This is due to insufficient path validation in the qckply_zip_theme() function, which appends a user-controlled 'stylesheet' parameter directly to the theme root directory path without sanitizing directory traversal sequences. This makes it possible for unauthenticated attackers to trigger the creation of a ZIP archive containing arbitrary files from the server's filesystem — including wp-config.