{"cve":"CVE-2026-42359","nvd":{"published":"2026-06-01T09:16:18.907","modified":"2026-07-21T19:10:00.107","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-502"],"references":["https://github.com/apache/airflow/pull/65915","https://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s","https://www.cve.org/CVERecord?id=CVE-2026-33858"],"products":["apache:airflow"],"source":"nvd","synced_at":"2026-10-19T22:37:48.043517290+00:00"},"epss":{"cve":"CVE-2026-42359","score":0.00571,"percentile":0.47257,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-wr76-29cr-67w8","url":"https://osv.dev/vulnerability/GHSA-wr76-29cr-67w8","summary":"Apache Airflow has a Deserialization of Untrusted Data vulnerability","modified":"2026-07-09T21:26:23.223875006Z","packages":[{"ecosystem":"PyPI","name":"apache-airflow","purl":"pkg:pypi/apache-airflow","ranges":[">=3.2.0 <3.2.2"],"fixed":["3.2.2"]}]},{"id":"PYSEC-2026-185","url":"https://osv.dev/vulnerability/PYSEC-2026-185","summary":"","modified":"2026-07-13T16:45:06.377267047Z","packages":[{"ecosystem":"PyPI","name":"apache-airflow","purl":"pkg:pypi/apache-airflow","ranges":[">=3.2.0 <3.2.2"],"fixed":["3.2.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}