The Multiline files upload for contact form 7 plugin for WordPress is vulnerable to unauthorized plugin deactivation due to a missing capability check on the mfcf7_zl_custom_handle_deactivation_plugin_form_submission() function in all versions up to, and including, 2.8.1. This makes it possible for authenticated attackers, with Subscriber-level access and above, to deactivate the plugin and send a custom reason from the site.