As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLIGHT 4959 - DURING CLIMB-OUT OF CVG, THE CABIN AND COCKPIT HAD A STRONG ODOR ASSOCIATED WITH HAZE IN CABIN, CREW DECLARED AN EMERGENCY AND RETURNED TO THE FIELD. FLIGHT LANDED WITHOUT INCIDENT. REPLACED THE LEFT AND RIGHT COALESCER SOCKS.