What’s Vulnerable › Vulnerabilities

CVE-2026-48207: Apache Fory: PyFory ReduceSerializer Incomplete Policy Enforcement

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-05-21 · updated 2026-07-23
• Weakness: CWE-502

Description

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.

Affected products

• Apache Software Foundation Apache Fory: from 0.13.0 before 1.0.0 — fixed in 1.0.0

How to fix

Upgrade to a fixed version: Apache Software Foundation Apache Fory 1.0.0. Check the vendor advisory for mitigations.

References

• https://fory.apache.org/security/#cve-2026-48207-pyfory-reduceserializer-deserializationpolicy-bypass
• http://www.openwall.com/lists/oss-security/2026/05/21/10

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