The YITH WooCommerce Wishlist plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 4.10.0 via the REST API endpoint and AJAX handler due to missing validation on user-controlled keys. This makes it possible for unauthenticated attackers to discover any user's wishlist token ID, and subsequently rename the victim's wishlist without authorization (integrity impact). This can be exploited to target multi-user stores for defacement, social engineering attacks, mass tampering, and profiling at scale.

The YITH WooCommerce Wishlist plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘id’ parameter in all versions up to, and including, 4.5.0 due to insufficient input sanitization and output escaping. 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.

The YITH WooCommerce Wishlist plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 4.10.0. This is due to the plugin not properly verifying that a user is authorized to perform actions on the REST API /wp-json/yith/wishlist/v1/lists endpoint (which uses permissioncallback => 'returntrue') and the AJAX deleteitem handler (which only checks nonce validity without verifying object-level authorization). This makes it possible for unauthenticated attackers to disclose wishlist tokens for any user and subsequently delete wishlist items by chaining the REST API authorization bypass with the exposed deleteitem nonce on shared wishlist pages and the AJAX handler's missing object-level authorization check.