In Jenkins Script Security Plugin version 1.36 and earlier, users with the ability to configure sandboxed Groovy scripts are able to use a type coerci...

In Jenkins Script Security Plugin version 1.36 and earlier, users with the ability to configure sandboxed Groovy scripts are able to use a type coercion feature in Groovy to create new File objects from strings. This allowed reading arbitrary files on the Jenkins master file system. Such a type coercion is now subject to sandbox protection and considered to be a call to the new File(String) constructor for the purpose of in-process script approval.