The WP SMS – Messaging & SMS Notification for WordPress, WooCommerce, GravityForms, etc plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 6.5. This is due to missing or incorrect nonce validation on the 'delete' action of the wp-sms-subscribers page. This makes it possible for unauthenticated attackers to delete subscribers via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
https://github.com/wp-sms/wp-sms/commit/0f36e2f521ade8ddfb3e04786defe074370afb50