Classloading problem "NoClassDefFoundError: net/sf/ehcache/Ehcache" when using CXF library with Ehcache

Issue

• ClassNotfoundException (CNF) when depending on JBoss CXF Module and packaging Ehcache library in WEB-INF/lib where Spring is also used.
• In the initial configuration of our Web Application we use ehcache.2.7.0.jar in WEB-INF/lib (we use Spring and ehcache for same utilities). Using CXF for Web Services calls, at runtime we have the following exception:

java.lang.NoClassDefFoundError: net/sf/ehcache/Ehcache

Full stacktrace

java.lang.NoClassDefFoundError: net/sf/ehcache/Ehcache
    at org.apache.cxf.ws.security.tokenstore.EHCacheTokenStoreFactory.newTokenStore(EHCacheTokenStoreFactory.java:34)
    at org.apache.cxf.ws.security.policy.interceptors.IssuedTokenInterceptorProvider.createTokenStore(IssuedTokenInterceptorProvider.java:107)
    at org.apache.cxf.ws.security.policy.interceptors.IssuedTokenInterceptorProvider.getTokenStore(IssuedTokenInterceptorProvider.java:116)
    at org.apache.cxf.ws.security.policy.interceptors.IssuedTokenInterceptorProvider$IssuedTokenOutInterceptor.handleDelegation(IssuedTokenInterceptorProvider.java:232)
    at org.apache.cxf.ws.security.policy.interceptors.IssuedTokenInterceptorProvider$IssuedTokenOutInterceptor.issueToken(IssuedTokenInterceptorProvider.java:448)
    at org.apache.cxf.ws.security.policy.interceptors.IssuedTokenInterceptorProvider$IssuedTokenOutInterceptor.handleMessage(IssuedTokenInterceptorProvider.java:149)
    at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:262)
    at org.apache.cxf.endpoint.ClientImpl.doInvoke(ClientImpl.java:530)
    at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:463)
    at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:366)
    at org.apache.cxf.endpoint.ClientImpl.invoke(ClientImpl.java:319)
    at org.apache.cxf.frontend.ClientProxy.invokeSync(ClientProxy.java:96)
    at org.apache.cxf.jaxws.JaxWsClientProxy.invoke(JaxWsClientProxy.java:134)
    at $Proxy48.zCDAGCOOPITCUSTGETLIST(Unknown Source)
    at com.test.application.SAML2StateLess.methodA(SAML2StateLess.java:126)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
.. .. ..
Caused by: java.lang.ClassNotFoundException: net.sf.ehcache.Ehcache from [Module "org.apache.cxf.impl:main" from local module loader @51ab8a5 (finder: local module finder @1d505b41 (roots: /opt/jboss-eap-6.1/modules,/opt/jboss-eap-6.1/modules/system/layers/base))]
    at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:190)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:468)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClassChecked(ConcurrentClassLoader.java:456)
    at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398)
    at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:120)
    ... 93 more