This issue was reported in users@cxf
When the soap action value does not match the ws-addressing's action or that action is not supported by the endpoint, an exception is raised and an appropriate SOAP fault message must be returned, which is specified in
Currently, there are two issues:
1. the soap fault code is correctly set but the soap action value is not correctly set to http://www.w3.org/2005/08/addressing/fault.
2. if the endpoint defines a fault type that has no message part, an NPE is thrown and this can lead to an empty response instead of a fault response.