The WildFly Elytron project which has been added to provide security for WildFly 11 is also usable independently of the application server. The following blog post demonstrates how WildFly Elytron can be used to add security to Undertows HelloWorld example: - http://darranl.blogspot.co.uk/2017/09/using-wildfly-elytron-with-undertow... Regards, Darran Lofthouse.