As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED. GOT AURAL WARNING LAVATORY SMOKE MESSAGE AT CRUISE FOR ABOUT 5 SECS AND THEN WENT AWAY. CAME FROM RIGHT AFT LAVATORY, BUT NOBODY IN THE LAVATORY. MAINTENANCE REPLACED LAVATORY E SMOKE DETECTOR AT PER MM 26-17-15.