Temporary file created by CachedOutputStream is not deleted after exchange is completed

There seems to be an issue related to tmp file created by CachedOutputStream.

My issue:
1. send a SOAP request to CXF consumer with a attachment whose size is larger than 64K
2. In my bundle, I will get the attachment by following code:

from("cxf:bean:foobarEndpoint")
// foobarEndpoint is defined in bundle-context.xml
// <cxf:cxfEndpoint id="foobarEndpoint"
// serviceClass="com.mycompany.FooBar">
// </cxf:cxfEndpoint>
.doTry()
.to("log:myInboundLogRoute -> Start")
.process(retrieveAttachment())
.doCatch(Exception.class)
.doFinally()
//.process(removeAttachment())
.end()
.to("log:myInboundLogRoute -> End");

private Processor retrieveAttachment() {
return new Processor() {
public void process(Exchange exchange) throws Exception {
if (LOGGER.isDebugEnabled())
LOGGER.debug("retrieveAttachment start");
// handle attachments
java.util.Collection<org.apache.cxf.message.Attachment> atts = PhaseInterceptorChain
.getCurrentMessage().getAttachments();

if (LOGGER.isDebugEnabled())

{ LOGGER.debug("retrieveAttachment done"); }

}
};
}

3. After the exchange is completed, there is a tmp file left under /tmp/cxf-tmp-***/ directory, which has the same size of attachment.
Note:
a. If the size of attachment < 64k, there will be no tmp file left.
b. If in my bundle, I didn't invoke retrieveAttachment(), there will be no tmp file left.

It seems that CachedOutputStream is not closed by CXF properly after the exchange is completed. I got some description from CachedOutputStream.java.

037 /**
038 * This output stream will store the content into a File if the stream context size is exceed the
039 * THRESHOLD which's default value is 64K. The temp file will store in the temp directory, you
040 * can configure it by setting the TEMP_DIR property. If you don't set the TEMP_DIR property,
041 * it will choose the directory which is set by the system property of "java.io.tmpdir".
042 * You can get a cached input stream of this stream. The temp file which is created with this
043 * output stream will be deleted when you close this output stream or the all cached
044 * fileInputStream is closed after the exchange is completed.
045 */

This issues is happening both in both fuse4.2 and fuse4.3.