well...thats not very good. The light can come from the front ( leaking shutter). Not cheap to fix. Usually, if the light leak is contained in the image area and not spill onto the borders.
Leak from the back. Have a good look, and if the sealing is loose, you can try putting some black tape over the back once you have loaded the film; or a light trap material inside. High chance that will fix it. Usually light leak from the back spills over to the border area .
Ujjwal
P.S : BTW, this is a leaf shutter, isnt it?