Input validation vulnerability in Simple Membership 4.3.9

The Simple Membership plugin for WordPress is vulnerable to a security issue called Reflected Cross-Site Scripting. This means that someone who doesn’t have permission to access the site can inject malicious web scripts into pages by tricking a user into performing an action such as clicking on a link. All versions of the plugin up to 4.3.9 (exclusive) have this vulnerability because they do not properly sanitize user input or properly escape output. It is possible that this vulnerability is the same as CVE-2023-6882.