I have Googled it, but have not found official info on that.
The type certificate of the Boeing 737 provides the following table for the MAX:
Wikipedia gives 45,070 kg as the MAX 8's OEW and 20,882 kg as its maximum payload.
I have found on Jane's database 45.065kg for OEW. And MZFW is 65.950kg. Doing the math, one get 20.885kg. So, Wikipedia info is quite good.