The Newsletter Popup WordPress plugin through 1.2 does not have CSRF checks in some places, which could allow attackers to make logged in users perform unwanted actions via CSRF attacks as the wp_newsletter_show_localrecord page is not protected with a nonce.

The Newsletter Popup WordPress plugin through 1.2 does not sanitise and escape some of its settings, which could allow unauthenticated users to perform Stored Cross-Site Scripting attacks

OpenCart 3.x Newsletter Custom Popup was discovered to contain a SQL injection vulnerability via the email parameter at index.php?route=extension/module/so_newletter_custom_popup/newsletter.