As of now only ConstraintValidationExceptions thrown within JAXRSBeanValidationInvoker.invoke(..) method are exposed to ExceptionMapper processing chain.
But both validation framework and underlying validators can throw any other unchecked non-ConstraintValidationException-s, e.g. ValidationExceptions or any other RuntimeException.
At the same time only Fault causes are exposed to ExceptionMapper chain within JAXRSInvoker.
Please kindly wrap any non-Fault exceptions thrown within JAXRSBeanValidationInvoker.invoke(..) method into Fault instances so that they could be properly handled by exception mappers.