The EmbedPress – Embed PDF, Google Docs, Vimeo, Wistia, Embed YouTube Videos, Audios, Maps & Embed Any Documents in Gutenberg & Elementor plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's Wistia embed block in all versions up to, and including, 3.9.10 due to insufficient input sanitization and output escaping on the user supplied url. 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.