A stored cross-site scripting (XSS) vulnerability exists in the Shopware 6 installation interface at /recovery/install/database-configuration/. The c_database_schema field fails to properly sanitize user-supplied input before rendering it in the browser, allowing an attacker to inject malicious JavaScript. This vulnerability can be exploited via a Cross-Site Request Forgery (CSRF) attack due to the absence of CSRF protections on the POST request. An unauthenticated remote attacker can craft a malicious web page that, when visited by a victim, stores the payload persistently in the installation configuration. As a result, the payload executes whenever any user subsequently accesses the vulnerable installation page, leading to persistent client-side code execution.