The Contact Form 7 + Telegram plugin for WordPress is vulnerable to unauthorized modification of data and loss of data due to a missing capability check on the 'wpcf7_Telegram::ajax' function in versions up to, and including, 0.8.5. This makes it possible for authenticated attackers, with subscriber-level access and above, to approve, pause and refuse subscriptions.
https://plugins.trac.wordpress.org/changeset/3176353/cf7-telegram#file21
https://plugins.trac.wordpress.org/browser/cf7-telegram/tags/0.8.4/classes/wpcf7telegram.php#L537