The slots are selling for $3.7 million to $3.8 million, up from an average of $3.5 million for the 2012 broadcast on NBC, USA Today reported Friday.
The Super Bowl is nearly five months away -- Feb. 3.
"We have a handful of units left," said John Bogusz, executive vice president of sports sales at CBS. "We're pacing well ahead of last time we had the game."
Bogusz said the ads were 80 percent sold out at this time of year in 2010, the last year the Super Bowl was on CBS.