Apache Fory <1.0.0: Untrusted Deserialization via ReduceSerializer
CVE-2026-48207 Published on May 21, 2026
Apache Fory: PyFory ReduceSerializer Incomplete Policy Enforcement
Deserialization of untrusted data in Apache Fory PyFory. PyFory's ReduceSerializer could bypass documented DeserializationPolicy validation hooks during reduce-state restoration and global-name resolution. An application is vulnerable if it deserializes attacker-controlled data using PyFory Python-native mode with strict mode disabled and relies on DeserializationPolicy to restrict unsafe classes, functions, or module attributes.
This issue affects Apache Fory: from before 1.0.0.
Mitigation: Users of Apache Fory are recommended to upgrade to version 1.0.0 or later, which enforces DeserializationPolicy validation for the affected ReduceSerializer paths and thus fixes this issue.
Vulnerability Analysis
CVE-2026-48207 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.
Weakness Type
What is a Marshaling, Unmarshaling Vulnerability?
The application deserializes untrusted data without sufficiently verifying that the resulting data will be valid.
CVE-2026-48207 has been classified to as a Marshaling, Unmarshaling vulnerability or weakness.
Products Associated with CVE-2026-48207
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Affected Versions
Apache Software Foundation Apache Fory:- Version 0.13.0 and below 1.0.0 is affected.