Output validation vulnerability in Sign-up Sheets 2.3.2

The Sign-up Sheets plugin for WordPress has a security vulnerability in versions up to 2.3.2. This means that someone who is not logged in can potentially add harmful code through a process called deserialization. There is no known way for the attacker to take control of the system, but if there is another plugin or theme also installed, they may be able to delete files, access private information, or run their own code.