The YaySMTP and Email Logs: Amazon SES, SendGrid, Outlook, Mailgun, Brevo, Google and Any SMTP Service plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions 2.4.9 to 2.6.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Note: The vulnerability has been initially patched in version 2.4.8 and was reintroduced in version 2.4.9 with the removal of the wp_kses_post() built-in WordPress sanitization function.

Missing Authorization vulnerability in Smackcoders SendGrid for WordPress allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects SendGrid for WordPress: from n/a through 1.4.

The FluentSMTP – WP SMTP Plugin with Amazon SES, SendGrid, MailGun, Postmark, Google and Any SMTP Provider plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 2.2.82 via deserialization of untrusted input in the 'formatResult' function. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code. The vulnerability was partially patched in version 2.2.82.

The SendGrid for WordPress plugin for WordPress is vulnerable to unauthorized loss of data due to a missing capability check on the 'wp_mailplus_clear_logs' function in all versions up to, and including, 1.4. This makes it possible for authenticated attackers, with Subscriber-level access and above, to delete the plugin's log files.

Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection') vulnerability in Smackcoders SendGrid for WordPress allows SQL Injection.This issue affects SendGrid for WordPress: from n/a through 1.4.

The SendGrid WordPress plugin is vulnerable to authorization bypass via the get_ajax_statistics function found in the ~/lib/class-sendgrid-statistics.php file which allows authenticated users to export statistic for a WordPress multi-site main site, in versions up to and including 1.11.8.