The Theme Switcha plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'theme_switcha_list' shortcode in all versions up to, and including, 3.3 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
https://plugins.trac.wordpress.org/changeset/2979783/theme-switcha#file1
https://plugins.trac.wordpress.org/browser/theme-switcha/tags/3.3/inc/plugin-core.php#L445