We don't know that. We just know that CN is Class 100 or more.
We know, for sure, that the Beyonder made Kurse 4 times as strong as Thor.
And basically indestructible.
Nefaria is very far beyond the class 100 range. So is Thor. Nefaria is stronger than Thor, but I don't think four times. However, he does have a speed advantage here.
When Thor fought Kurse the second time he had his belt which made him two times stronger then him regularly when Beyonder found this out he increased Kurse strength so that he was still allot stronger. So he could be 4 times stronger then Thor or 100 times then Thor and thats Thor that is 2 times stronger then regular