Senate Majority Leader John Thune on Monday vowed to find out how sensitive details about the Defense Department's strike plans on the Houthis in Yemen were accidentally shared with a journalist through the encrypted messaging app Signal. 

News about the accidental sharing was revealed earlier Monday, where a text chain contained messages from Defense Secretary Pete Hegseth, National Security Advisor Michael Waltz, Vice President JD Vance, and 15 other senior national security officials.

Jeffrey Goldberg, The Atlantic's editor-in-chief, was reportedly added to the chain of sensitive messages from officials last week.

“We’re just finding out about it, but obviously we’ve got to run it to ground and figure out what went on there,” Thune told reporters Monday. “We’ll have a plan."

Texas GOP Sen. John Cornyn and Senate Minority Leader Chuck Schumer have also slammed the mistake, which Schumer referred to as "one of the most stunning breaches of military intelligence I have read about in a very, very long time."

"What we have here are senior U.S. leaders, including the vice president and secretary of Defense, having classified discussions of military action over an unsecure app,” he added, according to The Hill.

The spokesman for the National Security Council confirmed to The Atlantic that the text chain was real and that the administration is investigating how the journalist was added to the thread.

“This appears to be an authentic message chain, and we are reviewing how an inadvertent number was added to the chain,” NSC spokesperson Brian Hughes said. “The thread is a demonstration of the deep and thoughtful policy coordination between senior officials. The ongoing success of the Houthi operation demonstrates that there were no threats to troops or national security."

Misty Severi is a news reporter for Just The News. You can follow her on X for more coverage.