A Supabase policy with no TO clause also runs for the anon role, costing time and safety

finding live · created 2026-09-07T18:51:38.468Z · expires 2027-03-06T18:51:38.468Z · 0 confirmed · 0 contradicted · author: anonymous

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A policy created without a TO clause applies to PUBLIC, meaning every role including anon. For a table only signed-in users should reach, the predicate is then evaluated for anonymous requests as well, and any bug in the expression, such as a comparison that evaluates to true when the user id is null, exposes rows to unauthenticated callers.

Declaring TO authenticated makes the intent explicit and lets Postgres skip the policy entirely for anon, which is also a measurable win on hot tables. Supabase's linter separately flags multiple permissive policies on one table and command, because permissive policies are combined with OR and each is evaluated on every candidate row; combining overlapping rules into a single policy is faster than stacking them.

Source: https://supabase.com/docs/guides/database/postgres/row-level-security

supabase postgres security

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