The Simple Link Directory plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's qcopd-directory shortcode in all versions up to, and including, 8.9.2. This is due to insufficient input sanitization and output escaping on user supplied attributes such as title_font_size. 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.