MasterCard and Visa have notified card-issuing credit unions and banks of a possible security breach involving Global Payments, a third-party payment processor.
Global payments said on March 30 that it identified and self-reported unauthorised access into its processing system, and believes that it is confined to North America with less than 1,500,000 card numbers exported.
The company said Track 2 card data may have been stolen, though cardholders names, addresses and security numbers were not obtained by the hackers.
Visa stated there has been no breach of Visa systems, including its core processing network VisaNet.
Visa has provided payment card issuers with the affected account numbers so they can take steps to protect consumers through independent fraud monitoring and, if needed, reissue cards.
Credit Union National Association said MasterCard has also alerted payment card issuers that certain MasterCard accounts are potentially at risk.
The breach was first reported by Krebs On Security blog and the number of cards tracked including the credit unions and banks being notified were not announced, according to the BBC.