Apache Airflow scheduler deserializes task-controlled XCom values (CVE-2026-86829)
Dag authors control XCom values that the scheduler fully deserializes during dependency evaluation.
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CVE-2026-86829
XCom deserialization in Apache Airflow scheduler
- CVSS
- —
- EPSS
- <1%p21
- Published
- ·
- Modified
AI analysisSummaries by Vani AI
Apache Airflow scheduler deserializes XCom values written by tasks when evaluating dependencies. A Dag author controls the data deserialized in the scheduler process. This affects only deployments where Dag authors are less trusted than Deployment Managers. Upgrade to 3.4.0 or later to restrict evaluation to primitive values.
What to do: Upgrade to Apache Airflow 3.4.0 or later. No workaround available.
| Product | Affected | Fixed in |
|---|---|---|
| Apache Airflow | — | 3.4.0 |
Estimated exposure
nicheNo basis for an estimate.
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
Description · NVD
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.
- Weakness
- CWE-502