U.S. Bank reveals data breach involving credit card accounts

Jakub Porzyck

U.S. Bank is notifying some of its customers about personal information that was accidentally shared by one of the bank's third-party vendors, according to draft letters posted to the California Attorney General's website.

About 11,000 customers were affected after the vendor, a collections recovery group, accidentally shared the info, a U.S. Bank spokesperson told NBC News.

The incident occurred Sept. 27 and involved the sharing of information, including names, Social Security numbers, closed account numbers and outstanding balances. Customers with closed U.S. Bank credit card accounts were affected, the letter states.

The bank said the error was found immediately and that the recipients of the file all cooperated to secure the information. It said it did not believe there was any cause for concern or any risk to customers as a result of the breach. An employee immediately noticed the error, and the bank ultimately received a certificate of destruction of the information, the spokesperson said.

Still, the bank is offering affected customers two years of free access to an online credit monitoring service. The bank also recommends that affected customers remain vigilant and place fraud alerts on their credit files.

This article was originally published on NBCNews.com