As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO CUN DUE TO THE FLIGHT CREW REPORTING AN AFT CARGO DOOR OPEN INDICATION ON INITAL CLIMB OUT. THE AIRCRAFT LANDED SAFELY AT CUN WHERE IT TAXIED TO THE GATE UNDER ITS OWN TAXI, (OPEN)