{"id":"CVE-2026-42359","summary":"Apache Airflow: Authenticated RCE via XCom PATCH endpoint — XComUpdateBody missing FORBIDDEN_XCOM_KEYS validator","details":"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.","aliases":["BIT-airflow-2026-42359","GHSA-wr76-29cr-67w8","PYSEC-2026-185"],"modified":"2026-07-09T21:26:23.223875006Z","published":"2026-06-01T07:49:17.429Z","database_specific":{"cna_assigner":"apache","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42359.json","cwe_ids":["CWE-502"]},"references":[{"type":"WEB","url":"https://pypi.python.org"},{"type":"WEB","url":"https://www.cve.org/CVERecord?id=CVE-2026-33858"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42359.json"},{"type":"ADVISORY","url":"https://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42359"},{"type":"FIX","url":"https://github.com/apache/airflow/pull/65915"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/apache/airflow","events":[{"introduced":"37069948c093e4b6720ec4821ff0ed7d6c069935"},{"fixed":"21cbbf663b140f4a84cf123acb90328a6a4d30f5"}],"database_specific":{"extracted_events":[{"introduced":"3.2.0"},{"fixed":"3.2.2"}],"cpe":"cpe:2.3:a:apache:airflow:*:*:*:*:*:*:*:*","source":["AFFECTED_FIELD","CPE_RANGE"]}}],"versions":["task-sdk/1.2.2rc3","task-sdk/1.2.2","3.2.2rc3","3.2.2","task-sdk/1.2.2rc2","3.2.2rc2","task-sdk/1.2.2rc1","3.2.2rc1","python-client/3.2.1rc1","python-client/3.2.1","task-sdk/1.2.1rc3","task-sdk/1.2.1","3.2.1rc3","3.2.1","task-sdk/1.2.1rc2","3.2.1rc2","task-sdk/1.2.1rc1","3.2.1rc1","python-client/3.2.0rc1","python-client/3.2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42359.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}