Memory leak in micronaut-core

Micronaut is a JVM-based, full stack Java framework designed for building JVM web applications with support for Java, Kotlin and the Groovy language. In affected versions sending an invalid Content Type header leads to memory leak in DefaultArgumentConversionContext as this type is erroneously used in static state. ### Impact Sending an invalid Content Type header leads to memory leak in DefaultArgumentConversionContext as this type is erroneously used in static state. ### Patches The problem is patched in Micronaut 3.2.7 and above. ### Workarounds The default content type binder can be replaced in an existing Micronaut application to mitigate the issue: ```java package example; import java.util.List; import io.micronaut.context.annotation.Replaces; import io.micronaut.core.convert.ConversionService; import io.micronaut.http.MediaType; import io.micronaut.http.bind.DefaultRequestBinderRegistry; import io.micronaut.http.bind.binders.RequestArgumentBinder; import jakarta.inject.Singleton; @Singleton @Replaces(DefaultRequestBinderRegistry.class) class FixedRequestBinderRegistry extends DefaultRequestBinderRegistry { public FixedRequestBinderRegistry(ConversionService conversionService, List binders) { super(conversionService, binders); } @Override protected void registerDefaultConverters(ConversionService<?> conversionService) { super.registerDefaultConverters(conversionService); conversionService.addConverter(CharSequence.class, MediaType.class, charSequence -> { try { return…