CVE-2026-59242

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.

Score

CVSS 3.1 5.4 Medium

Status

Analyzed - security@apache.org

Published

2026-08-12

Last modified

2026-10-24

Weaknesses

CWE-502

Affected products

• Airflow (Apache)
• Apache Airflow (Apache Software Foundation)

References

• https://github.com/apache/airflow/pull/69378
• https://lists.apache.org/thread/dm0520yhh4mn7qknyoh45r2w6c5qg2mg
• http://www.openwall.com/lists/oss-security/2026/08/12/6