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TI-2026-42382 Aliases CVE-2026-59242GHSA-fcmm-42r9-mmmm

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

Priority LOW 25CWE-502Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and GitHub. Impact type from CWE-502.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00529 44th percentileScored 2026-11-07
Fix Fixed Apache Airflow (Apache Software Foundation): 3.0.0, 3.3.1apache-airflow (PyPI): 3.3.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ApacheApache Airflowbefore 3.0.03.0.0Patch availableCNA
ApacheApache Airflow3.0.0 to before 3.3.13.3.1Patch availableCNA
—apache-airflow (PyPI)before 3.3.13.3.1Patch availableGHSA-fcmm-42r9-mmmm
  • Apache Airflow VendorApache Affected before 3.0.0 Fixed in 3.0.0 Patch available CNA
  • Apache Airflow VendorApache Affected 3.0.0 to before 3.3.1 Fixed in 3.3.1 Patch available CNA
  • apache-airflow (PyPI) Vendor— Affected before 3.3.1 Fixed in 3.3.1 Patch available GHSA-fcmm-42r9-mmmm

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:apache:airflow:*:*:*:*:*:*:*:*before 3.3.1VulnerableApache
  • cpe:2.3:a:apache:airflow:*:*:*:*:*:*:*:* Versions before 3.3.1 Vulnerable ·Apache

Remediation

  • Fix · CNA Apache Airflow (Apache Software Foundation) Fixed in 3.0.0
  • Fix · CNA Apache Airflow (Apache Software Foundation) Fixed in 3.3.1
  • Fix · GHSA-fcmm-42r9-mmmm apache-airflow (PyPI) Fixed in 3.3.1 Advisory →

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Apache Airflow 3.3.1

    12 records Highest priority Priority MEDIUM 2 MEDIUM, 10 LOW

    Other records, highest priority first

    • TI-2026-47748 Apache Airflow: DAG-author remote code execution on the Scheduler via a Serde `Callback` deserialization gadgetPriority MEDIUM 41
    • TI-2026-41827 Deserialization of untrusted data in Apache AirflowPriority MEDIUM 41
    • TI-2026-47565 Apache Airflow: DAG-author remote code execution on the Scheduler via awaiting_input next_kwargs deserializationPriority LOW 39
    Show all 12 records →
  • Release ·

    Apache Airflow 3.0.0

    8 records Highest priority Priority LOW 8 LOW

    Other records, highest priority first

    • TI-2026-48479 Apache Airflow: Authorization bypass in the Backfill API through conflicting interpretations of the backfill idPriority LOW 33
    • TI-2026-48482 Apache Airflow: Cross-team authorization bypass in the asset materialization and dag-run result endpointsPriority LOW 29
    • TI-2026-48480 Apache Airflow: Bulk Variable and Connection endpoints record secret values in the audit log in cleartextPriority LOW 29
    Show all 8 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-59242
  2. 2026-10-03 Alias added: GHSA-fcmm-42r9-mmmm
  3. 2026-10-07 EPSS moved to the below the 50th percentile
  4. 2026-11-03 Fix available: [email protected], [email protected] · CNA

References

Patch 1

Advisory 3

Other 5

  • TI-2020-10905 Missing authentication in Apache Airflow KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-09638 OS command injection in Apache Airflow KEVCVSS 3.1HIGH 8.8
  • TI-2022-19017 Apache Airflow <2.4.0 has an RCE in a bash example CVSS 3.1HIGH 8.8
  • TI-2021-16140 Apache Airflow: Variable Import endpoint missed authentication check CVSS 3.1CRITICAL 9.8
  • TI-2022-08169 Apache Airflow: RCE in example DAGs CVSS 3.1HIGH 8.8
  • TI-2024-26776 Apache Airflow: DAG Author Code Execution possibility in airflow-scheduler CVSS 3.1HIGH 8.8
See all 157 →

Sources

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