Credit card companies Visa Inc. (NYSE:V) and MasterCard Inc (NYSE:MA) have just sent out an alert to warn customers and banks of a possible security breach.  The breach apparently happened anywhere between January  21 through February 25  and is reported as massive and could compromise over 10 million card numbers.  At press time, no word on which specific banks were affected.

Security expert Brian Krebs explained the current situation:

Affected banks are now starting to analyze transaction data on the compromised cards, in hopes of finding a common point of purchase. Sources at two different major financial institutions said the transactions that most of the cards they analyzed seem to have in common are that they were used in parking garages in and around the New York City area.

It’s not clear how many cards were breached in the processor attack, but a sampling from one corner of the industry provides some perspective. On Wednesday, PSCU — a provider of online financial services to credit unions — said it alerted 482 credit unions that appear to have had cards impacted by the breach, and that a total of 56,455 member VISA and MasterCard accounts were compromised. PSCU said fraudulent activity had been detected on a relatively small number of those cards — 876 accounts — and that the activity was geographically dispersed.

Right now, it’s speculated that an unnamed third-party processor was responsible for this security breach. MasterCard reportedly said that they would investigate the breach further.

This news is rather frightening to know. What’s even more scary is that according to ZDNet, certain cards  could have been compromised and if the full Track 1/Track 2 data has copied, it’s possible that there could be counterfeit cards made. The only thing we consumers can do is wait to hear more about the security breach as it’s reported and to keep a close eye on their cards.