Spacebar Server before commit 51da17c contains a missing authorization vulnerability that allows any authenticated user to enumerate complete guild membership by querying the GET /guilds/{guild_id}/roles/{role_id}/member-ids endpoint without guild membership verification. Attackers can exploit the unprotected route handler in the roles member-ids endpoint, which lacks permission checks present in sibling endpoints, to retrieve the full list of member user IDs for any guild on the instance using only a valid bearer token and a known guild ID.