Weird artifact w my Canon IV SB2

I just processed my first couple rolls from my new Canon Barnak style camera. It has a cloth shutter. On three exposures I got a weird flash in the same spot. Any ideas?

You can rule out a shutter issue if the mark extends past the edge of the frame lines. People will be able to help you more if you show an image of the whole negative filmstrip against a bright white background without cropping.

You seem to have a light leak which can have different causes. I would make a careful examination of the curtains and make sure they are smooth, soft, supple, with no wrinkles. Aging, dry shutter curtains that leak are a very common malady on all screw mount Leica's and Leica copies. If the curtains seem OK, I'd shoot another roll as sometimes leaks can occur during film handling, or for various reasons other reasons near the beginning or end of a roll. If the problem goes away you will probably be fine. Shoot your next test roll in sunlight, which is a good stress test for light leaks.