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 Fluent Forms plugin for WordPress by Fluent Forms plugin for WordPress is vulnerable to Stored Cross-Site Scripting in all versions up to, and including, 5.1.9 due to insufficient input sanitization and output escaping. This makes it possible for attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploitation level depends on who is granted the right to create forms by an administrator. This level can be as low as contributor, but by default is admin.