In Guide to Leica are three examples of veiling and ghosting flare with the Leica 50mm f/2 APO-Summicron-M ASPH.
The results are jaw-dropping, in a bad way. So disappointing that I must reevaluate my plans to obtain this lens until and unless Leica addresses it.
UPDATE: reader Peter W has confirmed the issue and I’ve added his comments to the flare page.
UPDATE 2: see possible explanation.
Note the flat-line shadow across the top area, apparently caused by the camera internally.