Editor's Note: For the latest on this story, go to Global Payments: Breach Contained, But Damage Done.

MasterCard and Visa are currently investigating a significant breach at a U.S.-based credit card processor.

"Sources in the financial sector are calling the breach 'massive,' and say it may involve more than 10 million compromised card numbers," writes Krebs on Security's Brian Krebs.

"The Wall Street Journal is reporting that the breached processor was Global Payments Inc., which processes credit and debit cards for banks and merchants," Krebs writes.

For more on this story, go to Global Payments: Breach Contained, But Damage Done.

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