The answer is yes, mostly. Below is an example of how to setup for receiving a CDA Message.
The real issue comes into play depending on how you need to receive the message and what needs to be done with it. CDA and HL7 v3 messaging is not as trivial as HL7 v2 (your typical pipe delimited HL7 message) is. The message structures are highly complex and will require a lot of learning. Additionally, CDA messages are not transferred over the MLLP protocol like HL7 v2. I have generally seen people transferring these messages using the XDS profiles. So, depending on how you need to receive the message, there may some additional work to be done.
I believe the paid/licensed version of Mirth offers some components to aid with CDA/HL7 v3 messages, but it is not included in the OSS version.
Receiving a CDA Message in Mirth
Mirth would have no issue receiving the XML message. Just make sure to set the data type to XML in the channel.

From there, you can setup your receive and destination. If you need to work with the XML of the CDA, in the message transformer make sure to provide a sample CDA in the message templates section. Once you do that, the message should show up in teh Message Trees section.
