The SEO Plugin by Squirrly SEO plugin for WordPress is vulnerable to blind SQL Injection via the 'search' parameter in all versions up to, and including, 12.4.05 due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for authenticated attackers, with Subscriber-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

The SEO Plugin by Squirrly SEO WordPress plugin before 11.1.12 does not escape the type parameter before outputting it back in an attribute in an admin page, leading to a Reflected Cross-Site Scripting

In the process of testing the SEO Plugin by Squirrly SEO WordPress plugin before 12.3.21, a vulnerability was found that allows you to implement Stored XSS on behalf of the editor by embedding malicious script, which entails account takeover backdoor