Although Superman is so much stronger and more powerful, etc than Venom, I still think Venom will win. It really depends of Venom's intelligence, if he can figure out to keep the Kryptonite hidden.
Superman prefers close combat. Surely he has hundreds of other weapons in his arsenal, but most often you see him get close to beat on the villain. Superman is arrogant that sorta way.
And when Superman is close... Then he's dead.
If they're going all out, Venom is dead.
Within ONE second Superman could do one of the following things.
Vapourise Venom And the k-nite with a blast of superheat from his eyes.
Freeze Venom solid THEN vapourise the k-nite, then shatter Venom with his fist.
Blow the K-Nite to smithereens with heat vision, then proceed to do whatever the hell he likes.
Venom doesn't stand a chance.
LOL this is the biggest mismatch ever, I mean do you not remember what happened when Wonderwoman and Superman were fighting and she tried to pull out Kryptonite on Superman ??? he just knocked it out of her hand into the Sun i mean sure kryptonite is a weakness for supes but if you havent noticed lately he has been showing a little resistance to it , or think back to Hush when Batman pulled out Kryptonite on Superman its not like Superman just hit the floor as soon as he saw it, even batman said that Superman was holdin back and if he wanted Batman dead he would of been, or if thats not enough think back to Superman/Batman when Superman had to fight Supergirl and wore a F***ing kryptonite ring and beat her down. So yea i think if you give Venom some kryptonite and for some reason Superman decides not to use any other power of his and is in the mood for a fist fight I still say venoms going down i mean if he can beat Supergirl while WEARING a kryptonite ring im sure he can beat venom.