CVE-2026-48207
CWE-502Published: May 21, 2026· Updated: May 22, 2026
Official 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.
Risk Analysis
This critical vulnerability (CVSS 9.8) in Apache Fory PyFory allows deserialization of untrusted data. The ReduceSerializer can bypass documented DeserializationPolicy validation hooks, enabling an attacker to execute arbitrary code or manipulate data if the application deserializes attacker-controlled data with strict mode disabled. This poses a significant risk to data integrity and system control.
No public exploit is currently known for this remotely exploitable vulnerability. The low attack complexity means an attacker could easily exploit this if the conditions are met.
Users of Apache Fory should upgrade to version 1.0.0 or later. This version enforces DeserializationPolicy validation for the affected ReduceSerializer paths, mitigating the issue. Ensure strict mode is enabled during deserialization if an immediate upgrade is not possible.
Technical Analysis
CVE-2026-48207 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
From a weakness classification perspective (CWE-502): Insecure deserialization vulnerabilities allow attackers to inject malicious objects during deserialization, potentially enabling remote code execution.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (2)
Quick Facts
Related CVEs (CWE-502)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-48207 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts