The Divi theme for WordPress is vulnerable to Stored Cross-Site Scripting via the skype_url shortcode attribute of the Social Media Follow module in all versions up to, and including, 4.27.6. This is due to a three-part sanitization failure: (1) the skype_url field is not included in the $url_options whitelist in class-et-builder-element.php, so it never invokes esc_url_raw() during shortcode processing, (2) the render code in SocialMediaFollowItem.php explicitly skips esc_url() for Skype URLs (! $is_skype ? esc_url( $url ) : $skype_url), and (3) only sanitize_text_field() is applied, which preserves single and double quote characters allowing attribute breakout. The unsanitized value is interpolated directly into a single-quoted href attribute (href='{$social_network_link_url}'). 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 interacts with the injected element.