published August 30, 2026
Improper Input Validation vulnerability in ash-project ash_graphql allows an unauthenticated client to crash a relay node(id: ...) query with an unhandled KeyError.
AshGraphql.Graphql.Resolver.resolve_node/2 decodes the client-supplied global ID with decode_relay_id/1, which only base64-decodes the string and splits it on : without validating the type segment. The decoded type is passed straight to Map.fetch!(type_to_domain_and_resource_map, type). Because fetch! raises on a missing key, a relay ID whose type segment is a valid atom that is not a relay-exposed type aborts the resolver before its resolve/2 clauses and their rescue handlers run, so the error never becomes a GraphQL error and may expose a stacktrace. Common resource names are easy to guess. The fix uses Map.fetch/2 and returns an Invalid node id error for unknown types.
This issue affects ash_graphql: from 0.27.0 before 1.11.0.