@neo4j/graphql library versions prior to 7.5.6 fail to verify the authenticity of a client-supplied, pre-decoded JWT object passed through GraphQL subscription connectionParams. As a result, any unauthenticated remote client that can open a GraphQL-over-WebSocket connection can forge arbitrary JWT claims (e.g. sub, roles) in connectionParams.jwt and have them accepted as authenticated identity for the purposes of @authentication and @subscriptionsAuthorization directive evaluation. This allows a fully unauthenticated attacker to receive subscription events that should be restricted to specific authenticated roles/users.
Upgrade the library to versions 7.5.6+ or 5.12.14+. v6 is end-of-life and will not receive a fix.
The application enables features.subscriptions and features.authorization, and wires the subscriptions transport (e.g. graphql-ws) to forward WebSocket connectionParams into the resolver context.
Fixed in 5.12.14 (LTS) and 7.5.6 (current). The 6.x line is end-of-life and will not receive a patch; users on 6.x must upgrade to 5.12.14+ or 7.5.6+.