FKIE_CVE-2026-42359

Vulnerability from fkie_nvd - Published: 2026-06-01 09:16 - Updated: 2026-07-21 19:10
Severity
8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
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.
References
security@apache.orghttps://github.com/apache/airflow/pull/65915Issue Tracking, Patch
security@apache.orghttps://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038sMailing List, Vendor Advisory
security@apache.orghttps://www.cve.org/CVERecord?id=CVE-2026-33858Third Party Advisory
Impacted products
Vendor Product Version
apache airflow *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://pypi.python.org",
          "defaultStatus": "unaffected",
          "packageName": "apache-airflow",
          "product": "Apache Airflow",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThan": "3.2.2",
              "status": "affected",
              "version": "3.2.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "security@apache.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:apache:airflow:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "D170BE0B-8FB0-455D-B886-AEA5677D12A8",
              "versionEndExcluding": "3.2.2",
              "versionStartIncluding": "3.2.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A bug in Apache Airflow\u0027s 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\u0027s 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 \u0027PATCH /api/v2/xcomEntries/{key}\u0027 permiti\u00f3 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, \u0027return_value\u0027) que el endpoint POST correspondiente ya validaba contra \u0027FORBIDDEN_XCOM_KEYS\u0027. El endpoint tambi\u00e9n aceptaba formas de carga \u00fatil serializadas que el deserializador del disparador trata como c\u00f3digo; combinado, esto permiti\u00f3 RCE en el disparador cuando la tarea afectada se aplaz\u00f3 a continuaci\u00f3n. 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 correcci\u00f3n de CVE-2026-33858: PR #64148 a\u00f1adi\u00f3 el validador \u0027FORBIDDEN_XCOM_KEYS\u0027 solo en la ruta POST/set; la ruta PATCH no estaba cubierta. Los usuarios que ya actualizaron para CVE-2026-33858 deber\u00edan actualizar adicionalmente a \u0027apache-airflow\u0027 3.2.2 o posterior para cubrir el bypass de la ruta PATCH."
    }
  ],
  "id": "CVE-2026-42359",
  "lastModified": "2026-07-21T19:10:00.107",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-42359",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-02T03:55:43.691388Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-06-01T09:16:18.907",
  "references": [
    {
      "source": "security@apache.org",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "url": "https://github.com/apache/airflow/pull/65915"
    },
    {
      "source": "security@apache.org",
      "tags": [
        "Mailing List",
        "Vendor Advisory"
      ],
      "url": "https://lists.apache.org/thread/g8dqykpf1p90tysq8tln4qtkqwb1038s"
    },
    {
      "source": "security@apache.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-33858"
    }
  ],
  "sourceIdentifier": "security@apache.org",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-502"
        }
      ],
      "source": "security@apache.org",
      "type": "Secondary"
    }
  ]
}



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