{"affected":[{"defaultStatus":"unaffected","ecosystem":"pypi","packageName":"apache-airflow-core","product":"Apache Airflow","source":"CNA: apache","vendor":"Apache Software Foundation","versions":[{"lessThan":"3.2.2","status":"affected","version":"3.2.0","versionType":"semver"}]}],"cveId":"CVE-2026-42359","cwes":["CWE-502"],"description":"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.","epss":{"date":"2026-11-02","percentile":0.47243,"score":0.00571},"exploits":[],"kev":null,"metrics":[{"score":8.8,"severity":"high","source":"ADP: CISA-ADP","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}],"modifiedAt":1793688975211,"publishedAt":1780300157429,"references":[{"source":"CNA: apache","tags":["patch"],"url":"https://github.com/apache/airflow/pull/65915"},{"source":"CNA: apache","tags":["vendor-advisory"],"url":"https://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s"},{"source":"CNA: apache","tags":["related"],"url":"https://www.cve.org/CVERecord?id=CVE-2026-33858"}],"remediation":[{"kind":"fix","source":"CNA: apache","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://github.com/apache/airflow/pull/65915"}],"revision":"a46a89ddb0a497b47a034a32f03ed3b35f1ec45ea22c79795f2245372837b5dc","sources":[{"modifiedAt":1793688975211,"name":"CNA: apache","retrievedAt":1793689753613,"url":"https://www.cve.org/CVERecord?id=CVE-2026-42359"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793689756527,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-42359"}],"ssvc":{"assessedAt":1780372543691,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"total"},"status":"published","title":"Apache Airflow: Authenticated RCE via XCom PATCH endpoint — XComUpdateBody missing FORBIDDEN_XCOM_KEYS validator","updatedAt":1793689756527}