Deserialization of Untrusted Data Affecting apache-airflow-core package, versions [,3.2.2)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-PYTHON-APACHEAIRFLOWCORE-17137551
- published3 Jun 2026
- disclosed1 Jun 2026
- creditJeff Vier, Anisto Mejin, Venkatraman Kumar
Introduced: 1 Jun 2026
CVE-2026-42359 (opens in a new tab)How to fix?
Upgrade apache-airflow-core to version 3.2.2 or higher.
Overview
Affected versions of this package are vulnerable to Deserialization of Untrusted Data via the XCom PATCH endpoint PATCH /api/v2/xcomEntries/{key} that allows an authenticated UI/API user with XCom write permission on a Dag to set XCom entries under reserved key names (e.g. return_value) that the matching POST endpoint already validated against FORBIDDEN_XCOM_KEYS. The endpoint also accepts serialized payload shapes that the triggerer's deserializer treats as code; combined, this allowed RCE on the triggerer when the affected task next deferred.
Note:
This is only exploitable in deployments where untrusted users have XCom write permission on Dags that defer to the triggerer.
Details
Serialization is a process of converting an object into a sequence of bytes which can be persisted to a disk or database or can be sent through streams. The reverse process of creating object from sequence of bytes is called deserialization. Serialization is commonly used for communication (sharing objects between multiple hosts) and persistence (store the object state in a file or a database). It is an integral part of popular protocols like Remote Method Invocation (RMI), Java Management Extension (JMX), Java Messaging System (JMS), Action Message Format (AMF), Java Server Faces (JSF) ViewState, etc.
Deserialization of untrusted data (CWE-502) is when the application deserializes untrusted data without sufficiently verifying that the resulting data will be valid, thus allowing the attacker to control the state or the flow of the execution.