CVE-2026-111421
Apache Airflow: Execution API: set_xcom skips the reserved-key check, so task-written XComs instantiate airflow.* classes on the API server
Description
Apache Airflow's Task Execution API stored XCom values written by a task without the reserved-key check applied elsewhere, so a Dag author's task could write an XCom that, when a user later viewed it through the API with deserialization enabled, made the API server instantiate classes from the `airflow.*` namespace with arguments the Dag author chose. This is an incomplete fix for CVE-2026-59242: users who applied that fix in apache-airflow 3.3.1 remain affected through this route and should upgrade to apache-airflow 3.4.0 or later.
INFO
Published Date :
Nov. 9, 2026, 10:17 a.m.
Last Modified :
Nov. 9, 2026, 10:17 a.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Upgrade Apache Airflow to version 3.4.0 or later.
- Ensure reserved-key checks are enforced for XCom values.
- Review and sanitize XCom data from untrusted sources.
- Disable XCom deserialization when viewing sensitive data.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-111421.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-111421 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-111421
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2026-111421 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-111421 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
Nov. 09, 2026
Action Type Old Value New Value Added Description Apache Airflow's Task Execution API stored XCom values written by a task without the reserved-key check applied elsewhere, so a Dag author's task could write an XCom that, when a user later viewed it through the API with deserialization enabled, made the API server instantiate classes from the `airflow.*` namespace with arguments the Dag author chose. This is an incomplete fix for CVE-2026-59242: users who applied that fix in apache-airflow 3.3.1 remain affected through this route and should upgrade to apache-airflow 3.4.0 or later. Added CWE CWE-502 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/111xxx/CVE-2026-111421.json">CVE-2026-111421</a> Added Reference https://github.com/apache/airflow/pull/72718 Added Reference https://github.com/apache/airflow/pull/74829 Added Reference https://lists.apache.org/thread.html/pwdwx354tv0x3m8wzfhh59r6wyztj2lk Added Reference https://www.cve.org/CVERecord?id=CVE-2026-59242