Hong Kong flag carrier Cathay Pacific said Wednesday it had suffered a data leak affecting up to 9.4 million passengers.

“We acted immediately to contain the event, commence a thorough investigation with the assistance of a leading cybersecurity firm, and to further strengthen our IT security measures,” Cathay Pacific Chief Executive Officer Rupert Hogg said in a statement on the airline’s website.

“We have no evidence that any personal data has been misused,” he added.