EBWS fails to handle WS-Security header with soap:mustUnderstand="1" in SOA-P with CXF

Issue

• After switching the WS stack to CXF, EBWS throws SOAP Faults when it receives SOAP requests with the WS-Security UsernameToken header which is declared along with soap:mustUnderstand="1".
• I have set up <security moduleName="..."/> for the EBWS in jboss-esb.xml to enable WS-Security.
• I used the following SOAP request:

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:say="http://www.jboss.org/sayHi" xmlns:cust="http://www.jboss.org/custom-request" xmlns:sub="http://www.jboss.org/custom-subtype" xmlns:t="http://www.jboss.org/type2">
   <soap:Header>
      <wsse:Security soap:mustUnderstand="1" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd">
         <wsse:UsernameToken>
            <wsse:Username>kermit</wsse:Username>
            <wsse:Password>thefrog</wsse:Password>
         </wsse:UsernameToken>
      </wsse:Security>
   </soap:Header>
   <soap:Body>
      ...
   </soap:Body>
</soap:Envelope>

• And got the following SOAP Fault:

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
   <soap:Header>
      <wsse:Security soap:mustUnderstand="1" xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd"/>
   </soap:Header>
   <soap:Body>
      <soap:Fault>
         <faultcode>soap:MustUnderstand</faultcode>
         <faultstring>MustUnderstand headers: [{http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd}Security] are not understood.</faultstring>
      </soap:Fault>
   </soap:Body>
</soap:Envelope>

• I also got the following error stacktrace:

WARNING [PhaseInterceptorChain] Interceptor for {http://soa.jboss.org/ESBServiceSample}HelloWorldPubServiceService#{http://soa.jboss.org/ESBServiceSample}HelloWorldPubServiceOp has thrown exception, unwinding now
org.apache.cxf.binding.soap.SoapFault: MustUnderstand headers: [{http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd}Security] are not understood.
        at org.apache.cxf.binding.soap.interceptor.MustUnderstandInterceptor$UltimateReceiverMustUnderstandInterceptor.handleMessage(MustUnderstandInterceptor.java:225)
        at org.apache.cxf.binding.soap.interceptor.MustUnderstandInterceptor$UltimateReceiverMustUnderstandInterceptor.handleMessage(MustUnderstandInterceptor.java:199)
        at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:243)
        at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:111)
        at org.apache.cxf.transport.servlet.ServletDestination.invoke(ServletDestination.java:99)
        at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:431)
        at org.jboss.wsf.stack.cxf.ServletControllerExt.invoke(ServletControllerExt.java:173)
        at org.jboss.wsf.stack.cxf.RequestHandlerImpl.handleHttpRequest(RequestHandlerImpl.java:61)
        at org.jboss.wsf.stack.cxf.CXFServletExt.invoke(CXFServletExt.java:185)
        ...