As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 5237 - DURING TAXI-OUT OF CVG THE CABIN FILLED WITH SMOKE, CREW DECLARED AN EMERGENCY. DEPLANED PASSENGERS ON TAXI-WAY AND BUSSED BACK TO THE TERMINAL. VERIFIED THAT THE RIGHT ACM HAD SEIZED, DEFERRED THE RIGHT ACM PER MEL 21-51-01.