The Sunshine Photo Cart is a plugin for WordPress that allows photographers to create free client photo galleries. However, this plugin has a security vulnerability called Reflected Cross-Site Scripting. This means that unauthenticated attackers can inject harmful web scripts into pages, potentially tricking users into clicking on a harmful link. This vulnerability exists in all versions of the plugin up to 3.2.5 due to inadequate measures taken to clean and protect user input and output.