The Allow HTML in Category Descriptions plugin for WordPress is vulnerable to Stored Cross-Site Scripting via category descriptions in all versions up to, and including, 1.2.4. This is due to the plugin unconditionally removing the wp_kses_data output filter for term_description, link_description, link_notes, and user_description fields without checking user capabilities. This makes it possible for authenticated attackers, with administrator-level access and above, to inject arbitrary web scripts in category descriptions that will execute whenever a user accesses a page where the category description is displayed. This only affects multi-site installations and installations where unfiltered_html has been disabled.