Severity: important Affected versions:
- Apache Airflow (apache-airflow) before 3.3.0 Description: A bug in `BaseSerialization.deserialize()` allowed unrestricted `import_string()` of attacker-controlled class paths when the Scheduler / API Server loaded a serialized DAG: a DAG author could embed a malicious trigger into a DAG to gain remote code execution on the API Server / Scheduler process, crossing the Airflow security boundary that DAG-author code must never execute in those processes. Users are advised to upgrade to `apache-airflow` 3.3.0 or later. As a defense-in-depth mitigation, deployments where DAG-author trust is limited can restrict the `[core] allowed_deserialization_classes` config to a narrow allowlist. Credit: Ziyu Lin (finder) bugbunny.ai (tool) intadd (GitHub handle: @intadd) (finder) K (finder) Amogh Desai (@amoghrajesh) (remediation developer) Jarek Potiuk (remediation developer) References: https://github.com/apache/airflow/pull/66002 https://github.com/apache/airflow/pull/68528 https://airflow.apache.org/ https://www.cve.org/CVERecord?id=CVE-2026-33264
