Apache Airflow allows code execution through unsafe serialized DAG deserialization

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.

CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Severity from

GitHub (reviewed advisory)

Weakness

CWE-502

Also known as

BIT-airflow-2026-33264, CVE-2026-33264, PYSEC-2026-2082

• nvd.nist.gov/vuln/detail/CVE-2026-33264
• github.com/apache/airflow/pull/66002
• github.com/apache/airflow/pull/68528
• github.com/apache/airflow/commit/69b6c54ef17b048ebb0e9a656d0d9e1c99480d6b
• github.com/apache/airflow/commit/7e9bdb245e09373d91fcb7bda575ad4be63aa28d
• github.com/apache/airflow
• github.com/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-2082.yaml
• lists.apache.org/thread/otvdw8qt2y7xy2n5nq9xby9ky4rf5ltj
• www.openwall.com/lists/oss-security/2026/07/07/1