Severity: important
Affected versions:
- Apache Airflow (apache-airflow) before 3.3.1
Description:
Apache Airflow's XCom `GET /api/v2/{...}/xcomEntries/{key}?deserialize=true`
endpoint passed a string-literal payload through `BaseXCom.deserialize_value`
without the `_check_forbidden_xcom_keys` guard, allowing an authenticated API
user with XCom write-and-read access to instantiate arbitrary `airflow.*`
classes on the API server (CWE-502). An authenticated user who can write an
XCom value and then read it back with `deserialize=true` triggers the unsafe
instantiation. Users are advised to upgrade to apache-airflow 3.3.1 or later,
which rejects reserved XCom serialization keys submitted as JSON string
literals.
Credit:
localhost-detect (@localhost-detect) (finder)
Jarek Potiuk (remediation developer)
References:
https://github.com/apache/airflow/pull/69378
https://airflow.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-59242
