Apache Airflow up to 3.2.x Trigger BaseSerialization.deserialize deserialization

Summaryinfo

A vulnerability categorized as critical has been discovered in Apache Airflow up to 3.2.x. This issue affects the function BaseSerialization.deserialize of the component Trigger Handler. Such manipulation leads to deserialization. This vulnerability is uniquely identified as CVE-2026-33264. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Apache Airflow up to 3.2.x. It has been rated as critical. Affected by this issue is the function BaseSerialization.deserialize of the component Trigger Handler. The manipulation with an unknown input leads to a deserialization vulnerability. Using CWE to declare the problem leads to CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-33264 since 03/18/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/07/2026).

Upgrading to version 3.3.0 eliminates this vulnerability.

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Productinfo

Type

• Business Process Management Software

Vendor

• Apache

Name

• Airflow

Version

• 3.0
• 3.1
• 3.2

License

• open-source

Website

• Vendor: https://www.apache.org/
• Product: https://github.com/apache/airflow/

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