A glitch on Aerpolan’s Web site revealed personal information of program members for a short time on July 26, CBC News reported.
Net surfers who visited the site were able to view member profiles, including home addresses, phone numbers, dates of birth, mileage account balances and past account history.
The information was available for two hours, until IBM Canada shut the site down.
Air Canada has insisted that passwords and credit card numbers were not revealed.
Aeroplan told the CBC that the problem was internal, and not the result of computer hackers.