SOAP Fault "MustUnderstand headers: [{}Security] are not understood."

Solution Unverified - Updated -


  • We are using Jboss-cxf for publishing web service and wss4j for authentication and configured accordingly in cxf.xml.
  • We pass the below as a part of soap header along with the request:
    <!--WSSE Security Header-->
    <wsse:Security soapenv:mustUnderstand="1" xmlns:wsse="">
      <wsse:UsernameToken wsu:Id="UsernameToken-17644953" xmlns:wsu="">
        <wsse:Password Type="">yyyyyyyyy</wsse:Password>
  • when we test through soapUI we get sometimes the below error:
<soap:Envelope xmlns:soap="">
         <faultstring>MustUnderstand headers: [{}Security] are not understood.</faultstring>
  • when we change the value of mustUnderstand as "0" in the SOAP request then it works, but many times it works with mustUnderstand as "1" as well.


  • Red Hat JBoss Enterprise Application Platform (EAP)
    • 6.x

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