It a complicated question. It sort of depends on the living arrangement.
Could they get in trouble? yes, its a factual question really, the prosecutor would have to prove they had constructive possession. This means they should have known about the stuff upon reasonable inquiry/smell. And that they exercised some right of control over the place where it was stored.
So would a prosecutor charge them. Probably not, its too much trouble. this all revolves around several factors.
1.) Do you have a lock on your door? Do they? Factors that indicate that its all common space rather then a dormitory like arrangement.