CVE-2026-59242 Apache Airflow: Arbitrary airflow.* class instantiation on the API server via the XCom deserialize endpoint
Authenticated users can trigger arbitrary class instantiation on the API server via the XCom deserialize endpoint, potentially leading to code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-59242?
CVE-2026-59242 is a medium-severity unsafe deserialization vulnerability in Apache Airflow, published on 12 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-502
Which versions are affected by CVE-2026-59242?
4 open source packages ship an affected version, including apache-airflow and airflow. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
apache-airflow PyPI | All versions | 3.3.1 |
apache-airflow PyPI | All versions | 3.3.1 |
apache-airflow PyPI | All versions | 3.3.1 |
airflow Bitnami | All versions | 3.3.1 |
Products include Apache Airflow.
How do I fix CVE-2026-59242?
Upgrade apache-airflow to 3.3.1 or later.
Upgrade, and only deserialise data from trusted sources or with an allow-list of types. More about Unsafe deserialization.
Is CVE-2026-59242 being exploited?
There is no known exploitation of CVE-2026-59242 in the wild and no public exploit code.
Other vulnerabilities in Apache Airflow
- CVE-2020-13927 Apache Airflow's Experimental API Authentication Bypass
- CVE-2020-11978 Apache Airflow Command Injection
- CVE-2026-33264 Apache Airflow: DAG author RCE on webserver via unrestricted import_string() in BaseSerialization.deserialize()
- CVE-2023-25754 Apache Airflow: Privilege escalation using airflow logs
- CVE-2023-22884 Apache Airflow, Apache Airflow MySQL Provider: Arbitrary file read via MySQL provider in Apache Airflow
Sources
Also known as BIT-airflow-2026-59242, CLEANSTART-2026-ZO32580, ECHO-48cd-35f6-43fd, GHSA-fcmm-42r9-mmmm, MINI-5hv7-25g6-mp47, MINI-mgv6-qgv3-r3j9 and 1 more.