As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS NOT GROUNDED: IN CRUISE, LAVATORY SMOKE ALERT DISPLAYED ON ECAM. FLIGHT ATTENDANTS CHECKED BOTH AFT LAVATORIES AND DID NOT SEE OR SMELL SMOKE. MAINTENANCE PERFORMED SATISFACTORY OPERATIONAL CHECK OF LAVATORY SMOKE DETECTION SYSTEM PER AMM 26-18-00.