That Napoleon had knowledge of widespread corruption in his Empire, I have no doubt.
That he personally enriched himself along the way...? I don't see much logic in that. After 1800 he lived at the expense of the state. What need would he have had to "embezzle" money? What would he have done with it, that he couldn't have done legally?
The use of state/military power to seize other people's property(ies) all across Europe, and then to give those properties to his family or subordinates as rewards... That isn't "corruption" in the classic sense of the word. I'm not sure what to call it, other than "confiscation" and "patronage." There isn't really any equivalent practice that I'm aware of, in the existing precedence of the Old Regime monarchies. (Which again makes sense, since the basis of their power was acceptance by a landed aristocracy, who wouldn't have taken kindly to the confiscation of their turf.)
But in all 4000+ of those cases, I'm not aware of a single instance in which Napoleon gave the property to himself.