I have heard clips very occasionally credited to CNN and those could be TV audio clips. Other than that, it has been only CBS actualities and CBS special reports for the last year or two. The NBC Radio News is new this week.Well, CNN doesn't have a radio outlet anymore. Many stations that had CNN via Westwood One now have NBC Radio News. Despite the name, it's an iHeart service, pulling some world and national clips from NBC News, just as Westwood One News used to pull clips from CNN.
If I remember, WSB once was affiliated with ABC, then with CBS.