Currently there are 1.7 million customers who use the app, but only about 1% may have been compromised. As a result, the company has decided to lock down all 1.7 million accounts as a precaution until customers change their passwords.

The airline told customers in an email that it “recently detected unusual log-in behaviour with Air Canadas mobile App between August 22-24, 2018.”

The app stores basic information such as a user’s name, email address and telephone number, all of which could have been improperly accessed. Moreover, additional data such as a customer’s Aeroplan number, passport number, Nexus number, known traveller number, gender, birth date, nationality, passport expiration date, passport country of issuance and country of residence could have been accessed, if users had them saved in their profile on the app. Any credit card information on file would have been encrypted and as such protected, the company continued.

Nevertheless, as long as app users still have a valid passport and other pieces of supporting documentation, the government says the risk of someone filing for and receiving a new passport in their names is low, according to online publication CBC Canada.