WPBakery Page Builder <= 8.6 - Authenticated (Contributor+) Stored Cross-Site Scripting

The WPBakery Page Builder plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'rev_slider_vc' shortcode in all versions up to, and including, 8.6 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. This is only exploitable when RevSlider is also installed.