We have recently upgraded Java web app a from DXA 1.5 to 1.8, however we found that there are security issues with jackson-databind versions before 2.9.8. 

With DXA 1.8 we are getting jackson-databind version 2.8.3 only. We have tried to override the version to 2.9.8, but it causing exception in DD4T as below:

> Servlet.service() for servlet
> [org.springframework.web.servlet.DispatcherServlet] in context with
> path [] threw exception [Handler processing failed; nested exception
> is java.lang.NoSuchMethodError:
> com.fasterxml.jackson.databind.util.ClassUtil.findClass(Ljava/lang/String;)Ljava/lang/Class;]
> with root cause java.lang.NoSuchMethodError:
> com.fasterxml.jackson.databind.util.ClassUtil.findClass(Ljava/lang/String;)Ljava/lang/Class;
> at
> org.dd4t.databind.serializers.json.TridionFieldTypeIdResolver.typeFromId(TridionFieldTypeIdResolver.java:97)
> at
> com.fasterxml.jackson.databind.jsontype.impl.TypeDeserializerBase._findDeserializer(TypeDeserializerBase.java:156)

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Then we tried to upgrade the DD4T version, but that also failed with below exception:

> SEVERE: Exception sending context initialized event to listener
> instance of class
> [org.springframework.web.context.ContextLoaderListener]
> org.springframework.beans.factory.BeanDefinitionStoreException: Failed
> to load bean class: com.sdl.dxa.DxaSpringInitialization; nested
> exception is java.io.FileNotFoundException: class path resource
> [org/dd4t/core/providers/BaseBrokerProvider.class] cannot be opened
> because it does not exist 	at
> org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:293)
> 	at
> org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:227)
> 	 Caused by: java.io.FileNotFoundException: class path resource
> [org/dd4t/core/providers/BaseBrokerProvider.class] cannot be opened
> because it does not exist 	at
> org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:157)

	

Can you please provide any suggestion on this . Really appreciate your help.