Title: Apache Airflow de Apache Software Foundation, Description: Un error en el endpoint PATCH de XCom de Apache Airflow 'PATCH /api/v2/xcomEntries/{key}' permitió a un usuario autenticado de UI/API con permiso de escritura de XCom en un Dag establecer entradas de XCom bajo nombres de clave reservados (por ejemplo, 'return_value') que el endpoint POST correspondiente ya validaba contra 'FORBIDDEN_XCOM_KEYS'. El endpoint también aceptaba formas de carga útil serializadas que el deserializador del disparador trata como código; combinado, esto permitió RCE en el disparador cuando la tarea afectada se aplazó a continuación. Afecta a implementaciones donde usuarios no confiables tienen permiso de escritura de XCom en Dags que se aplazan al disparador. Esto es un bypass de la corrección de CVE-2026-33858: PR #64148 añadió el validador 'FORBIDDEN_XCOM_KEYS' solo en la ruta POST/set; la ruta PATCH no estaba cubierta. Los usuarios que ya actualizaron para CVE-2026-33858 deberían actualizar adicionalmente a 'apache-airflow' 3.2.2 o posterior para cubrir el bypass de la ruta PATCH.

{"timestamp":"2026-06-02T03:55:43.691388Z","id":"CVE-2026-42359","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}

[{"vendor":"Apache Software Foundation","product":"Apache Airflow","defaultStatus":"unaffected","collectionURL":"https://pypi.python.org","packageName":"apache-airflow","versions":[{"version":"3.2.0","lessThan":"3.2.2","versionType":"semver","status":"affected"}]}]

OR
          *cpe:2.3:a:apache:airflow:*:*:*:*:*:*:*:* versions from (including) 3.2.0 up to (excluding) 3.2.2

Apache Software Foundation: https://github.com/apache/airflow/pull/65915 Types: Issue Tracking, Patch

Apache Software Foundation: https://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s Types: Mailing List, Vendor Advisory

Apache Software Foundation: https://www.cve.org/CVERecord?id=CVE-2026-33858 Types: Third Party Advisory

AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

https://www.cve.org/CVERecord?id=CVE-2026-33858

A bug in Apache Airflow's XCom PATCH endpoint `PATCH /api/v2/xcomEntries/{key}` allowed an authenticated UI/API user with XCom write permission on a Dag to set XCom entries under reserved key names (e.g. `return_value`) that the matching POST endpoint already validated against `FORBIDDEN_XCOM_KEYS`. The endpoint also accepted serialized payload shapes the triggerer's deserializer treats as code; combined, this allowed RCE on the triggerer when the affected task next deferred. Affects deployments where untrusted users have XCom write permission on Dags that defer to the triggerer. This is a fix-bypass of CVE-2026-33858: PR #64148 added the `FORBIDDEN_XCOM_KEYS` validator only on the POST/set path; the PATCH path was not covered. Users who already upgraded for CVE-2026-33858 should additionally upgrade to `apache-airflow` 3.2.2 or later to cover the PATCH-path bypass.

CWE-502

https://github.com/apache/airflow/pull/65915

https://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s