Very small scale. There are accounts of British and US soldiers raping and, I think in one case (accidentally) killing a German would be rape victim.
And a Canadian Unit went haywire but that was in response to a Waffen SS massacre of their own soldiers.
Both US and UK/Commonwealth still had a death penalty for such crimes I understand.
I believe we still had a potential death penalty for soldiers guilty of raping or looting. That's probably a key factor.
What certainly didn't happen is Oradour Sur Glanes and Lidices everywhere the Western Allies went. Even into Germany there are no records of such happening. It would have come out if so. It was only 73-74 years ago !!
The Soviet side of things is difficult. Somewhat a case of the German Army sowing the wind and the German civilian population reaping the whirlwind. Sad, but hard to understand unless you've had your entire or part of your family systematically wiped out by the German Army I guess.