Threats affecting pkg:github/supabase/realtime

Supabase Realtime provides Broadcast, Presence, and Postgres Changes via WebSockets. Prior to version 2.103.1, the REST broadcast endpoints accept an expired JWT when the exp claim is encoded as a JSON string instead of a JSON number. The same route rejects an expired integer exp token signed with the same tenant secret. The accepted request returns 202 and emits the broadcast to subscribers. This could allow an unauthenticated attacker can broadcast realtime messages to subscribers. The attack can be performed via the Internet/only from within the supabase project. The impact of broadcasting messages to subscribers is application specific. This issue has been patched in version 2.103.1.

CVE-2026-62247 is an authorization vulnerability in Supabase Realtime prior to version 2.111.2. The issue arises when a private-channel client is allowed presence.write permission but denied presence.read permission under a differential row-level security policy. In this scenario, the client can receive presence_diff messages revealing other members' presence metadata such as location, online status, and typing information. Deployments without differential presence visibility or those only using postgres_changes data are not affected. The vulnerability is fixed in version 2.111.2.