The Freemius SDK, as used by hundreds of WordPress plugin and theme developers, was vulnerable to Cross-Site Request Forgery and Information disclosure due to missing capability checks and nonce protection on the _get_debug_log, _get_db_option, and the _set_db_option functions in versions up to, and including 2.4.2. Any WordPress plugin or theme running a version of Freemius less than 2.4.3 is vulnerable.

The Custom post types, Custom Fields & more plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's shortcode and custom post meta in all versions up to, and including, 5.0.4 due to insufficient input sanitization and output escaping on user supplied post meta values. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The Custom Post Types and Custom Fields creator WordPress plugin before 2.3.3 does not sanitize and escape some of its settings, which could allow high-privilege users such as admin to perform Stored Cross-Site Scripting attacks even when the unfiltered_html capability is disallowed (for example, in multisite setup).