CVE-2026-59242

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

Published Aug 12, 2026 CVSS 3.1 · 5.4 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-fcmm-42r9-mmmm Apache Airflow XCom API permits unsafe deserialization through JSON string literals
History
Type Values Removed Values Added
CPEs cpe:2.3:a:apache:airflow:*:*:*:*:*:*:*:*
Type Values Removed Values Added
First Time appeared Apache
Apache airflow
Vendors & Products Apache
Apache airflow
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Apache Airflow: Arbitrary airflow.* class instantiation on the API server via the XCom deserialize endpoint
Weaknesses CWE-502
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
apache
Published
Updated
Nov 3, 2026, 6:58 AM
Reserved
Jul 4, 2026, 12:17 AM
Status
Analyzed
Published
Aug 12, 2026, 4:17 PM
Modified
Nov 3, 2026, 7:20 AM