Apache Airflow up to 3.3.x Scheduler deserialization

Summaryinfo

A vulnerability classified as critical has been found in Apache Airflow up to 3.3.x. Impacted is an unknown function of the component Scheduler. This manipulation causes deserialization. This vulnerability is registered as CVE-2026-86829. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Apache Airflow up to 3.3.x and classified as critical. Affected by this vulnerability is some unknown processing of the component Scheduler. The manipulation with an unknown input leads to a deserialization vulnerability. The CWE definition for the vulnerability is CWE-502. The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Apache Airflow's scheduler fully deserializes XCom values written by task code while evaluating task dependencies. A Dag author, who controls what a task writes to XCom, therefore controls data that is deserialized inside the scheduler process - a context the Airflow security model reserves for code installed by the Deployment Manager, above the worker-scoped execution capability a Dag author is documented to have. Deployments that treat Dag authors as less trusted than Deployment Managers are affected, and the scheduler must be evaluating a task dependency that reads a task-written XCom value. Users of apache-airflow are recommended to upgrade to version 3.4.0 or later, which restricts dependency evaluation to primitive XCom values.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-86829 since 09/08/2026. The exploitation appears to be easy. The attack can be launched remotely. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 11/09/2026).

Upgrading to version 3.4.0 eliminates this vulnerability.

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Productinfo

Type

• Business Process Management Software

Vendor

• Apache

Name

• Airflow

Version

• 3.0
• 3.1
• 3.2
• 3.3

License

• open-source

Website

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

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