Vulnerability-Lookup

GHSA-FCMM-42R9-MMMM

Vulnerability from github – Published: 2026-08-12 18:31 – Updated: 2026-08-12 18:31

Details

Apache Airflow's XCom GET /api/v2/{...}/xcomEntries/{key}?deserialize=true endpoint passed a string-literal payload through BaseXCom.deserialize_value without the _check_forbidden_xcom_keys guard, allowing an authenticated API user with XCom write-and-read access to instantiate arbitrary airflow.* classes on the API server (CWE-502). An authenticated user who can write an XCom value and then read it back with deserialize=true triggers the unsafe instantiation. Users are advised to upgrade to apache-airflow 3.3.1 or later, which rejects reserved XCom serialization keys submitted as JSON string literals.

Severity

5.4 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-59242"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-12T16:17:09Z",
    "severity": "MODERATE"
  },
  "details": "Apache Airflow\u0027s XCom `GET /api/v2/{...}/xcomEntries/{key}?deserialize=true` endpoint passed a string-literal payload through `BaseXCom.deserialize_value` without the `_check_forbidden_xcom_keys` guard, allowing an authenticated API user with XCom write-and-read access to instantiate arbitrary `airflow.*` classes on the API server (CWE-502). An authenticated user who can write an XCom value and then read it back with `deserialize=true` triggers the unsafe instantiation. Users are advised to upgrade to apache-airflow 3.3.1 or later, which rejects reserved XCom serialization keys submitted as JSON string literals.",
  "id": "GHSA-fcmm-42r9-mmmm",
  "modified": "2026-08-12T18:31:18Z",
  "published": "2026-08-12T18:31:18Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59242"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apache/airflow/pull/69378"
    },
    {
      "type": "WEB",
      "url": "https://lists.apache.org/thread/dm0520yhh4mn7qknyoh45r2w6c5qg2mg"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/08/12/6"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-59242 (GCVE-0-2026-59242)

Vulnerability from cvelistv5 – Published: 2026-08-12 15:35 – Updated: 2026-09-16 14:55

Title

Apache Airflow: Arbitrary airflow.* class instantiation on the API server via the XCom deserialize endpoint

Summary

Apache Airflow's XCom `GET /api/v2/{...}/xcomEntries/{key}?deserialize=true` endpoint passed a string-literal payload through `BaseXCom.deserialize_value` without the `_check_forbidden_xcom_keys` guard, allowing an authenticated API user with XCom write-and-read access to instantiate arbitrary `airflow.*` classes on the API server (CWE-502). An authenticated user who can write an XCom value and then read it back with `deserialize=true` triggers the unsafe instantiation. Users are advised to upgrade to apache-airflow 3.3.1 or later, which rejects reserved XCom serialization keys submitted as JSON string literals.

Severity

5.4 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-12 16:41 UTC

CWE

CWE-502 - Deserialization of Untrusted Data

Assigner

apache mitre root

References

3 references

URL	Tags
https://github.com/apache/airflow/pull/69378	patch
https://lists.apache.org/thread/dm0520yhh4mn7qkny…	vendor-advisory
http://www.openwall.com/lists/oss-security/2026/08/12/6

Impacted products

1 product

Vendor	Product	Version
Apache Software Foundation	Apache Airflow	Affected: 0 , < 3.3.1 (semver)

Credits

localhost-detect (@localhost-detect) Jarek Potiuk

Show details on NVD website

JSON

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    "adp": [
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              "attackVector": "NETWORK",
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              "baseScore": 5.4,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "LOW",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
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          },
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                "timestamp": "2026-08-12T16:41:51.650384Z",
                "version": "2.0.3"
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          "dateUpdated": "2026-08-12T16:41:55.648Z",
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          "shortName": "CISA-ADP"
        },
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        "providerMetadata": {
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        "references": [
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            "url": "http://www.openwall.com/lists/oss-security/2026/08/12/6"
          }
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-FCMM-42R9-MMMM

CVE-2026-59242 (GCVE-0-2026-59242)

Tags

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