CVE-2026-33264: Apache Airflow allows code execution through unsafe serialized DAG deserialization
A bug in BaseSerialization.deserialize() allowed unrestricted importstring() 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.
Published Jul 7, 2026 · Updated Sep 4, 2026
Affected packages
apache-airflow
- Ecosystem
- PyPI
- Affected
- < 3.3.0
- Fixed in
- 3.3.0
- Check
pip show apache-airflow
Advisory details
From the GitHub Advisory Database (CC BY 4.0).
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.
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-33264
- https://github.com/apache/airflow/pull/66002
- https://github.com/apache/airflow/pull/68528
- https://lists.apache.org/thread/otvdw8qt2y7xy2n5nq9xby9ky4rf5ltj
- https://github.com/apache/airflow/commit/69b6c54ef17b048ebb0e9a656d0d9e1c99480d6b
- https://github.com/apache/airflow/commit/7e9bdb245e09373d91fcb7bda575ad4be63aa28d
- https://github.com/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-2082.yaml
- https://github.com/advisories/GHSA-2943-9672-r45w
How this page is made: the data panel comes from the GitHub Advisory Database, CISA’s KEV catalog, the NVD and FIRST EPSS, and updates twice a day. No analysis has been written for this entry yet. Methodology