The The Slim SEO – AI SEO Plugin, Lightweight, Fast & Automated plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 4.11.1 This is due to the software allowing users to execute an action that does not properly validate a value before running doshortcode. This makes it possible for authenticated attackers, with subscriber-level access and above, to execute arbitrary shortcodes. A Subscriber-level user need only save the shortcode payload to their own Biographical Info field via the REST API or wp-admin profile page; the shortcode then executes on any unauthenticated front-end request that resolves that author's description, such as requests using the ?author= query parameter when autoredirection is disabled.

The Slim SEO – Fast & Automated WordPress SEO Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's slimseobreadcrumbs shortcode in all versions up to, and including, 4.5.3 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.