the media wants you to believe that this election was rigged.
but, the opposition boycotted the vote.
so, it's quite clear that maduro won - the opposition refused to vote.
a more pressing question is what would have happened if the opposition would have shown up. as this has been going on for years, it's not clear how close it would be.
and, i mean, of course there's going to be some irregularities - there are everywhere. but, you fundamentally cannot claim an election was rigged when the opposition didn't show up; the government wasn't even given the opportunity to meaningfully rig it.
https://www.nytimes.com/2018/02/21/world/americas/venezuela-election-opposition-boycott.html