BIT-AIRFLOW-2026-58076 Apache Airflow: Unguarded import_string() of airflow_exc_ser / base_exc_ser exception nodes in BaseSerialization.deserialize enables DAG-author RCE on Scheduler / API Server

Apache Airflow's serialization layer reconstructed exception nodes by calling importstring on a class name taken from the serialized blob and instantiating it with arguments from the same blob, with no restriction on what could be imported. An operator's executorconfig reaches that branch, so a D...