As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5300 - EN ROUTE JFK-BNA RECEIVED A CABIN DOOR AND LATCH CAUTION MESSAGE, CREW DECLARED AN EMERGENCY AND RETURNED TO JFK. FLIGHT LANDED WITHOUT INCIDENT. PRESSURIZED AIRCRAFT, ALL INDICATIONS NORMAL. DISCREPANCY COULD NOT BE DUPLICATED BY MAINTENANCE.