The WPBakery Page Builder Addons by Livemesh plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the [lvca_carousel] and [lvca_posts_carousel] shortcode attributes in all versions up to, and including, 3.9.4 due to insufficient input sanitization and output escaping. Specifically, shortcode attributes are encoded with wp_json_encode() and output into single-quoted data-settings HTML attributes without using esc_attr(), allowing attackers to break out of the attribute by injecting single quotes. 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.