The One Click Upsell Funnel for WooCommerce – Funnel Builder for WordPress, Create WooCommerce Upsell, Post-Purchase Upsell & Cross Sell Offers that Boost Sales & Increase Profits with Sales Funnel Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's wps_wocuf_pro_yes shortcode in all versions up to, and including, 3.4.9 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.