Apache Airflow: Authenticated RCE via XCom PATCH endpoint — XComUpdateBody missing FORBIDDEN_XCOM_KEYS validator_CVE-2026-42359

{
    "lastseen": "",
    "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.",
    "published": "2026-06-01T07:49:17.429Z",
    "modified": "2026-06-02T13:03:40.834Z",
    "type": "cve",
    "title": "Apache Airflow: Authenticated RCE via XCom PATCH endpoint \u2014 XComUpdateBody missing FORBIDDEN_XCOM_KEYS validator",
    "source": "apache",
    "references": "https://github.com/apache/airflow/pull/65915\nhttps://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s\nhttps://www.cve.org/CVERecord?id=CVE-2026-33858",
    "id": "CVE-2026-42359",
    "bulletinFamily": "",
    "cwe": [
        "CWE-502"
    ],
    "cvelist": null,
    "sourceData": "Apache Software Foundation Apache Airflow 3.2.0",
    "sourceHref": "",
    "cvss": {
        "score": 8.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Apache Airflow",
    "version": "3.2.0",
    "vendor": "Apache Software Foundation",
    "ai_description": "Authenticated Remote Code Execution (RCE) vulnerability in Apache Airflow's XCom PATCH endpoint",
    "ai_severity": "High",
    "ai_vendor": "Apache Software Foundation",
    "ai_product": "Apache Airflow",
    "ai_version": "3.2.0, 3.2.1",
    "ai_score": 8.8
}