Jenkins GitHub Branch Source Plugin vulnerable to Server-Side Request Forgery

A server-side request forgery vulnerability exists in Jenkins GitHub Branch Source Plugin 2.3.4 and older in Endpoint.java that allows attackers with Overall/Read access to cause Jenkins to send a GET request to a specified URL. Additionally, this form validation method did not require POST requests, resulting in a CSRF vulnerability. As of version 23.5, this form validation method requires POST requests and the Overall/Administer permission.