Apache Airflow Vulnerable to Deserialization of Untrusted Data

Apache Airflow's scheduler-side deadline-reference decoder (`SerializedCustomReference.deserialize_reference`) imported and dispatched arbitrary class paths drawn from DAG-author-controlled serialized state without an allowlist or plugin-registry gate. A DAG author whose code reaches the scheduler , the default on single-host deployments where the DAG bundle is importable from the scheduler process , could embed a custom `DeadlineReference` whose serialized form named an attacker-controlled module path, causing the scheduler to `import_string(...)` and instantiate that class with a live SQLAlchemy session attached. Affects deployments where DAG-author code is less trusted than the scheduler process. Users are advised to upgrade to `apache-airflow` 3.2.2 or later.

CVSS 3.1

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

Severity from

GitHub (reviewed advisory)

Weakness

CWE-502

Also known as

BIT-airflow-2026-45360, CVE-2026-45360, PYSEC-2026-186

• nvd.nist.gov/vuln/detail/CVE-2026-45360
• github.com/apache/airflow/pull/61461
• github.com/apache/airflow/pull/66737
• github.com/apache/airflow
• github.com/pypa/advisory-database/tree/main/vulns/apache-airflow/PYSEC-2026-186.yaml
• lists.apache.org/thread/q227dghjwgfz8xsxrf2pwpz4wk43zm83
• www.openwall.com/lists/oss-security/2026/05/31/12