CNN is reporting that according to Capital One, a hacker gained access to more than 100 million Capital One customer accounts and credit card applications earlier this year.
They say that among other information, the data accessed included some Social Security numbers.
CNN says that the Department of Justice arrested 33-year-old Paige Thompson in connection to the breach.
The department alleges that Thompson "posted on the information sharing site GitHub about her theft of information from the servers storing Capital One Data."
They say Thompson gained access by exploiting a misconfigured web application firewall according to the DOJ.
Capital One indicated it fixed the vulnerability and said it is "unlikely that the information was used for fraud or disseminated by this individual." The company is still investigating though.
Capital One says the breach affected around 100 million people in the U.S. and about 6 million in Canada.
However, Capital One says "no credit card account numbers or log-in credentials were compromised and over 99% of Social Security numbers were not compromised.
(CNN contributed to this report.)
