If it's remediable, then it can be fixed or cured. Your dog's bad breath, dangerous shopping habits, and poison ivy are all remediable afflictions.
Remediable is a formal way of describing something that can be fixed up because there's a remedy for it. Horace Mann, the first American advocate of public education, said that “evil is inevitable, but is also remediable” — meaning that even the most rotten kids can be reformed and rehabbed into model citizens. Today's detention hall monitors might disagree.