As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE AT FL450, MAIN CABIN DOOR WAS SQUEALING LOUDLY. LOWER ALTITUDE WAS SELECTED AND SQUEAL VOLUME LOWERED WITH ALTITUDE. LIGHT COULD BE SEEN COMING FROM MIDDLE RIGHT SIDE OF CABIN DOOR. REMOVED AND REPLACED THE PASSENGER DOOR SEAL IAW GL5500 AMM 52-11-37, OPS CHECK AND LEAK CHECK GOOD.