The Contact Manager plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'title’ parameter in all versions up to, and including, 8.6.5 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with administrator-level access, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This only affects multi-site installations and installations where unfiltered_html has been disabled.

The Contact Manager plugin for WordPress is vulnerable to arbitrary file uploads due to missing file type validation in the contact form upload feature in all versions up to, and including, 8.6.4. This makes it possible for unauthenticated attackers to upload arbitrary files on the affected site's server which may make remote code execution possible in specific configurations where the first extension is processed over the final. This vulnerability also requires successfully exploiting a race condition in order to exploit.