As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, CABIN AND FLIGHT CREW PERSONNEL SMELLED FUMES IN THE AIRCRAFT. CATPAIN AND FIRST OFFICER DONNED OXYGEN MASKS. AN UNEVENTFUL LANDING WAS MADE AT DESTINATION AIRPORT. MAINTENANCE FOUND THAT FUEL WAS BEING INGESTED INTO THE APU. SOURCE OF FUEL WAS FOUND TO BE A LEAK FROM APU FUEL CONTROL. REPLACED THE FUEL CONTROL.