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 AND THE AIRCRAFT RETURNED TO LAS DUE TO THE FLIGHT CREW REPORTING THAT WHILE CLIMBING THROUGH FL260 AN EXCESS CABIN ALTITUDE ECAM WARNING DISPLAYED. THE AIRCRAFT LANDED SAFELY AT LAS WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED CABIN PRESSURE CONTROLLER #1 (AALA202507174560) AND #2 (AALA202507170414) AND ACCOMPLISHED A SATISFACTORY OPERATIONAL CHECK WITH NO FAULTS NOTED.