Message contents and government official contact information were obtained during the breach, 404 Media reports.

Mike Waltz's exit from the Trump administration comes on the heels of the Signal chat scandal. Here's what happened.

A phone app that Mike Waltz, President Donald Trump’s former national security adviser, apparently used to save his text ...

A photo taken this week showed Mike Waltz using an app that looks like—but is not—Signal to communicate with top officials.

More than a month after he drew criticism for using Signal to discuss an impending military attack, Waltz was seen using what ...

President Donald Trump says he is nominating national security adviser Mike Waltz as United Nations ambassador while ...

"I think it will be a brutal confirmation hearing," Sen. Mark Warner said of Mike Waltz. "I think he's going to have tough ...

Researchers uncover security weaknesses in obscure TM SGNL app and indications that its Israeli maker was itself recently ...

The hacker reportedly gained access to customer data from TeleMessage, a Signal-like app that Waltz was seen using during a ...

Waltz was among high-ranking members of the administration who accidentally shared plans about a forthcoming U.S. military ...

National security adviser Mike Waltz and his deputy, Alex Wong, are exiting the administration, CBS News’s Jennifer Jacobs ...

President Donald Trump's outgoing national security adviser Mike Waltz was photographed using Signal on his phone during ...