The Senate Commerce Committee has issued a subpoena requiring former Yahoo CEO Marissa Mayer to testify before the committee in a hearing regarding cybersecurity breaches, a source with knowledge of the matter told The Hill.

This report was separately confirmed by a committee spokesperson on Tuesday.

The committee issued the subpoena on Oct. 25 after Mayer declined multiple requests to testify voluntarily, even after being threatened with legal action. Following the subpoena order, Mayer’s representative told the committee that she would comply and testify before the committee, according to the spokesperson.

The Senate Commerce Committee’s top Democrat, Sen. Bill Nelson Clarence (Bill) William NelsonDemocrats sound alarm on possible election chaos Trump, facing trouble in Florida, goes all in NASA names DC headquarters after agency's first Black female engineer Mary W. Jackson MORE (D-Fla.) supported Committee Chairman John Thune John Randolph ThuneWhat Senate Republicans have said about election-year Supreme Court vacancies The Hill's 12:30 Report - Presented by Facebook - Don't expect a government check anytime soon The Hill's Morning Report - Sponsored by The Air Line Pilots Association - Trump contradicts CDC director on vaccine, masks MORE’s (R-S.D.) move to subpoena Mayer, allowing the committee to avoid voting on the summon.

ADVERTISEMENT

Mayer’s representative asked if the committee would lift the subpoena order, as a part of a move to make the once-Yahoo CEO’s testimony appear voluntary, according to another source.

The committee spokesperson said that as of Tuesday, the subpoena is still in effect, but declined to comment on if it would be withdrawn as a result of Mayer’s reversal.

A representative for Mayer disputed this version of the events and stressed that she is appearing voluntarily.

According to her spokesperson, there was a back and forth with Mayer's representatives and the committee in which she stressed that she was not the best witness for the most recent 2017 disclosure of the 2013 breach in which 3 billion Yahoo accounts were compromised. After it was confirmed that a representative from Verizon would also testify, Mayer agreed to appear; however, the subpoena had already been issued at this point.

Individuals who do not appear before Congress when summoned can be held in contempt of Congress, which is a federal misdemeanor. Those found in contempt can face a maximum $1,000 fine and a maximum one-year sentence in federal prison, though actual instances of contempt are rare.

The former Yahoo CEO is being compelled to testify before the committee to comment on data breaches. In 2013 and 2014, Yahoo endured massive data breaches in which the data in billions of users' accounts was compromised.

Mayer’s initial decision to not appear before the committee raises accountability questions with the large-scale breaches. Mayer was in charge of the company during the 2013 and 2014 cyberattacks.

Since the cyberattacks came to light in 2016, Yahoo has been broken up and portions of it have been sold to Verizon. Those portions now operate under the moniker Oath.

The remaining bits of the firm operate as Altaba, which owns a significant stake in the Chinese digital commerce and technology platform Alibaba.

Equifax’s interim CEO Paulino do Rego Barros and its former CEO Richard Smith will also testify at the hearing, which is scheduled for Wednesday.

Equifax was the subject of a record-breaking cyberattack in July that compromised important information, like Social Security numbers, of 145.5 million Americans.

Smith has already testified before a slew of congressional panels who have blasted his former company's security practices.

- This report was updated at 1:41 p.m.