As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED ON ARRIVAL TO BUF DUE TO A YELLOW HYDRAULIC SYSTEM LOW PRESSURE AND RESERVOIR LOW LEVEL ECAM MESSAGES. THAT AIRCRAFT LANDED SAFELY AND TAXIED TO THE GATE UNDER ITS OWN POWER. MAINTENANCE REPLACED THE YELLOW HYDRAULIC SYSTEM PRIORITY VALVE DUE TO IT BEING CRACKED AND LEAKING PER AMM 29-13-33. A SATISFACTORY OPERATIONAL / LEAK CHECK WAS ACCOMPLISHED.