5 Supabase RLS Mistakes Founders Make (and How to Avoid Them)

A practical checklist for avoiding the most common Row Level Security pitfalls that lead to accidental data exposure.

Supabase makes it easy to ship fast — but the most painful leaks are usually configuration mistakes. Here are five RLS pitfalls we see repeatedly when auditing early-stage products.

1) Forgetting to Enable RLS on a Table

Policies don’t matter if RLS is disabled. Treat “RLS enabled” as a deployment checklist item for every table that contains user or business data.

2) Overly Broad SELECT Policies

The classic mistake is a policy that allows all authenticated users to read all rows. Prefer policies that scope access to the current user’s tenant or resource ownership.

3) Missing INSERT/UPDATE Restrictions

Many teams lock down reads but forget writes. Make sure INSERT and UPDATE policies enforce the same tenant boundary as SELECT.

4) Trusting Client-Controlled Fields

Never let the client set sensitive fields like plan, role, or quotas. Use RLS plus server-side enforcement (triggers or service-role updates) to keep those fields immutable for end users.

5) Shipping with a Leaked Key in JS

An anon key is expected in the browser — but you still need strong RLS. The real risk comes from combining a leaked key with permissive policies.

If you want a quick sanity check, run a scan and focus on what tables are publicly readable or writable.