CVE-2026-42359
Full vulnerability record from the local CVENow database.
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.
View original CVE JSON
{
"id": "CVE-2026-42359",
"sourceIdentifier": "[email protected]",
"published": "2026-06-01T09:16:18.907",
"lastModified": "2026-11-03T07:20:20.853",
"vulnStatus": "Analyzed",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "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."
},
{
"lang": "es",
"value": "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."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "Apache Software Foundation",
"product": "Apache Airflow",
"defaultStatus": "unaffected",
"collectionURL": "https://pypi.python.org",
"packageName": "apache-airflow-core",
"packageURL": "pkg:pypi/apache-airflow-core",
"versions": [
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"version": "3.2.0",
"lessThan": "3.2.2",
"versionType": "semver",
"status": "affected"
}
]
}
]
}
],
"metrics": {
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"vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9
}
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"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-06-02T03:55:43.691388Z",
"id": "CVE-2026-42359",
"options": [
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{
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{
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"role": "CISA Coordinator",
"version": "2.0.3"
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},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-502"
}
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"configurations": [
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"references": [
{
"url": "https://github.com/apache/airflow/pull/65915",
"source": "[email protected]",
"tags": [
"Issue Tracking",
"Patch"
]
},
{
"url": "https://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s",
"source": "[email protected]",
"tags": [
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{
"url": "https://www.cve.org/CVERecord?id=CVE-2026-33858",
"source": "[email protected]",
"tags": [
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}
]
}