In go.etcd.io/etcd/server/v3 before 3.5.33, 3.6.14, and 3.7.1, an authenticated user with READ permission on a single key can bypass RBAC restrictions by initiating an open-ended range watch using clientv3.WithFromKey(). The Watch RPC handler normalized open-ended range ends prior to authorization checks, causing isWatchPermitted to evaluate the request as a single-key watch while the underlying watch stream received events for all keys lexicographically greater than or equal to the target key.