The goalkeeper joined the club on loan from Sparta Prague in January.
Newcastle have an option to turn the loan into a permanent move at the end of the season.
Dubravka has impressed since arriving at St James's Park – he kept a clean sheet against Manchester United on his debut – and he is keen to stay at the club.
United manager Benitez hinted at a move for Dubravka after Saturday's 2-1 defeat to Watford at Vicarage Road.
Asked about the possibility of a deal for Dubravka, Benitez said: "That's an easy decision. It depends on us."
Dubravka kept United in the game against Watford.
The 29-year-old made a series of first-half saves – including a penalty stop from Troy Deeney – during a fraught first half.
"He's a good keeper, and we know how important he is for our team," said Benitez.
"It was a pity he was exposed too much. I don't like to praise too much the keeper, it means you have been defending all the time. I prefer to talk about the great job of the strikers scoring goals. It was the opposite."
Newcastle are 10th in the Premier League ahead of tomorrow night's game against Tottenham Hotspur at Wembley.