Cross-site scripting vulnerability exists in FitNesse releases prior to 20220319, which may allow a remote unauthenticated attacker to execute an arbitrary script on the web browser of the user who is using the product and accessing a link with a specially crafted certain parameter.
https://jvn.jp/en/jp/JVN94521208/
https://github.com/unclebob/fitnesse/blob/master/SECURITY.md