As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FUSELAGE / SKIN CUTOUT / FS 967-981 / STRG. 26R-27R : INTERNAL CUTOUT DOUBLER CORROSION THE INTERNAL SURROUND DOUBLER AROUND A FUSELAGE CUTOUT FOR A LAVATORY VENT WAS FOUND CORRODED BETWEEN FS 967 & 981 AND BETWEEN STRINGERS 26R & 27R. THE CORROSION WAS REMOVED WITH 6" X 6" CUTOUT TO THE INTERNAL DOUBLER. THE CUTOUT WAS REPAIRED WITH AN EXTERNAL ALUMINUM DOUBLER PER ER/A 382767-14, REV B.