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.
History

Mon, 09 Nov 2026 11:30:00 +0000

Type Values Removed Values Added
References

Mon, 09 Nov 2026 10:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Apache Airflow: Deserialization of task-controlled XCom values in the Scheduler during dependency evaluation
Weaknesses CWE-502
References

cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published: 2026-11-09T09:52:44.345Z

Updated: 2026-11-09T10:13:19.317Z

Reserved: 2026-09-08T14:27:44.182Z

Link: CVE-2026-86829

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-09T10:17:13.757

Modified: 2026-11-09T11:17:26.480

Link: CVE-2026-86829

cve-icon Redhat

No data.