Supabase RLS: The Hidden Danger (And How to Find It Before Hackers Do)

You just launched your Supabase project. It works. Users are signing up. You're proud of it. Then you get a message: "Hey, I can see everyone's data." This happens more than you'd think. And the cause is almost always the same: Row Level Security was enabled, but the policies were wrong — or missing entirely. Let me show you exactly how this happens, how to check if your project is affected, and how to fix it. What Is RLS and Why Does It Matter? Supabase uses PostgreSQL's Row Level Security to control which rows a user can read, insert, update, or delete. When you enable it, access is denied by default — until you create policies that explicitly allow access. The problem: enabling RLS and creating correct policies are two separate steps. You can do one without the other. And Supabase's dashboard will show your table as "RLS enabled" — technically true, but completely misleading if you have no policies. The Most Common Mistake: Enabling RLS Without Policies Here's what a dangerous table