Best Buy is warning that some of its customers' payment information may have been compromised in a data breach.

The retailer is the latest company, along with Delta Air Lines and Sears, to report the cyberattack last fall against a third-party operator of its chat services. Best Buy says a "small fraction" of its online customer population may have been affected, whether or not chat services were used.

The software company, (24)7.ai, says it discovered and fixed the breach in October. The attack may have exposed customers' names, addresses, credit card numbers, card security codes and expiration dates.

Best Buy says it will directly contact any affected customers and they will not be liable for fraudulent charges. It will also offer free credit monitoring.