available on DVD
from here with English subtitles
https://czechmovie.com/d/mephisto-dvd-1001861/
Kino Lorber Blu Ray https://www.blu-ray.com/movies/Mephisto-Blu-ray/260431/
The back cover of this release touts a "stunning 4K restoration by the Hungarian National Film Archive", and in this case the hyperbole is not that overstated.