As many as 1.5 million Visa and MasterCard accounts may have been compromised by the recent Global Payments security breach, the payment processor announced this evening.

Credit card numbers may have been exported, but no customer names, addresses, or Social Security numbers were accessed, the company said in a statement. The company believes the breach, which was revealed Friday, was confined to North America.

The nature of the breach, which was originally pegged at 50,000 accounts, has not been revealed. The company also did not say whether it knew of any fraudulent charges resulting from the breach on Global Payments, which processes payments from credit, debit, and gift cards between merchants and banks.

The company said it believes the incident has been contained and it is working with third parties to investigate the incident and minimize impact on customers, although it did not describe those efforts.

"We are making rapid progress toward bringing this issue to a close," CEO Paul Garcia said in the statement.

MasterCard and Visa have already sent out notices to their customers who may have been affected, informing them of the possible risk.

As a result of the breach, Visa removed Global Payments from its list of approved service providers. Visa told The Wall Street Journal (subscription required) that the move was in response to "Global Payments' reported unauthorized access." Visa said it has invited Global Payments to re-apply for validation by submitting evidence that its security is in compliance with Visa's standards.

Global Payments is scheduled to hold a conference call at 5 a.m. PT Monday to provide further information on the incident. Check back with CNET for full coverage.