What is King Duncan's reaction to the news that Cawdor is a traitor? What will happen to his title?

King Duncan is completely shocked by the news that the Thane of Cawdor has deceived him. Duncan trusted this man implicitly, and Cawdor betrayed him. As a result, Duncan has Cawdor executed and his title given to Macbeth.

He was a gentleman on whom I built
An absolute trust.

Act 1 Sc 4