Can you hear the price tag dropping?

Yahoo announced its sale to Verizon in late July, and yet the acquisition could fall through given the unexpectedly massive breach of at least 500 million Yahoo user accounts.

Verizon's lawyers said that there is a "reasonable basis" for them to withdraw from the deal, which has yet to close.

"I think we have a reasonable basis to believe right now that the impact is material and we're looking to Yahoo to demonstrate to us the full impact. If they believe that it's not then they'll need to show us that," Verizon general counsel Craig Silliman said at a Verizon event Thursday in Washington, D.C, according to Reuters.

In September, Yahoo confirmed that data from at least 500 million user accounts had been stolen in 2014, the scale of which could make it one of the largest data breaches in history.

When Yahoo officially admitted the breach, Verizon released a quite stunning statement, exposing that it received news of the security incident twodaysbefore the public announcement.

That was two months after Verizon announced it had would acquire Yahoo's core business for $4.83 billion.

Interestingly, Verizon CEO Lowell McAdam speaking earlier this week at a tech conference in San Francisco seemed optimistic about the deal.

"I'm not that shocked. It’s not a question of if you're going to get hacked — it’s when you’re going to get hacked," McAdam said, according to Business Insider. "I think people are going to realize that this is the state of the way the internet operates."

A story from the New York Postlast week alleged that Verizon was interested in a $1 billion discount. Verizon declined to comment Thursday if there were talks to renegotiate the price with Yahoo.

Yahoo said in a statement following reports, “We are confident in Yahoo’s value and we continue to work towards integration with Verizon.”

Editor's note: A previous version of this story stated Lowell McAdam is the CEO of Yahoo. He runs Verizon.