Invisible Anti-Spam & CAPTCHA < 5.1.1 - Subscriber+ Arbitrary Form Submission Deletion

The Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms WordPress plugin before 5.1.1 does not check the user's capabilities in its message deletion AJAX action, and only tests that a nonce parameter is present rather than validating it, allowing any authenticated user, such as a subscriber, to permanently delete every form submission the Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms WordPress plugin before 5.1.1 has stored.