The ConvertKit WordPress plugin before 2.0.5 does not validate and escapes some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as a contributor to perform Stored Cross-Site Scripting attacks, which could be used against high-privilege users such as admins.

The ConvertKit WordPress plugin before 2.2.1 does not escape a parameter before outputting it back in an attribute, leading to a Reflected Cross-Site Scripting which could be used against high privilege users such as admin

Insertion of Sensitive Information into Log File vulnerability in ConvertKit.This issue affects ConvertKit: from n/a through 2.4.5.

The ConvertKit – Email Newsletter, Email Marketing, Subscribers and Landing Pages plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the tag_subscriber function in all versions up to, and including, 2.4.9. This makes it possible for unauthenticated attackers to subscribe users to tags. Financial damages may occur to site owners if their API quota is exceeded.