Massachusetts Senator Elizabeth Warren is taking Wells Fargo's consumer accounts scandal straight to the top of the bank.

"There is a serious problem with senior management at Wells Fargo," Warren told CNBC Thursday. "There's a big problem at Wells Fargo."

Wells Fargo was fined a total of $185 million by regulatory agencies including the Consumer Financial Protection Bureau that accused the bank of creating as many as 1.5 million deposit accounts and 565,000 credit card accounts that consumers never asked for. The San Francisco-based banking giant fired 5,300 employees over the course of about five years as a result of the accounts.

As part of a settlement, Wells Fargo neither admitted nor denied the allegations.



Warren, a vocal critic of the big U.S. banks who originally proposed and later led the U.S. Consumer Financial Protection Bureau, said she is not satisfied with CEO John Stumpf's response to the crisis thus far.

"You can't have a scandal of this size and not have some senior management who are personally responsible," she said. "That's what I want to hear from him."