The Related Posts for WordPress plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.2.1. This is due to missing or incorrect nonce validation on the handlecreatelink() function. This makes it possible for unauthenticated attackers to add related posts to other posts via a forged request granted they can trick a site administrator into performing an action such as clicking on a link. This ultimately makes it possible for attackers to view draft and password protected posts.

Unvalidated input and lack of output encoding within the Related Posts for WordPress plugin before 2.0.4 lead to a Reflected Cross-Site Scripting (XSS) vulnerability within the 'lang' GET parameter while editing a post, triggered when users with the capability of editing posts access a malicious URL.