CVE-2026-33858: Apache Airflow: Unsafe Deserialization via Legacy Serialization Keys (__type/__var) Bypass in XCom API

[Rahul Vats <rahulvats () apache org>]

Severity: low 

Affected versions:

- Apache Airflow (apache-airflow) 3.1.8 before 3.2.0

Description:

Dag Authors, who normally should not be able to execute code in the webserver context could craft XCom payload causing 
the webserver to execute arbitrary code. Since Dag Authors are already highly trusted, severity of this issue is Low.


Users are recommended to upgrade to Apache Airflow 3.2.0, which resolves this issue.

Credit:

wooseokdotkim (finder)
Amogh Desai (remediation developer)

References:

https://github.com/apache/airflow/pull/64148
https://airflow.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-33858