by Kastro
Paper/Archive/CVE-2026-48207

CVE-2026-48207

Apache Software Foundation Apache Fory — Apache Fory: PyFory ReduceSerializer Incomplete Policy Enforcement

EPSS 0.6%CVSS 9.8
critical.is priorityof 100
39
CVSS 9.8 (ADP)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 47.4.474 × 209.5No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
Apache Fory0.13.0 – < 1.0.01.0.0CNA

Scores by source

CISA ADP9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

advisoryfory.apache.org/security/#cve-2026-48207-pyfory-reduceserializer-deserializationpolicy-bypassrefopenwall.com/lists/oss-security/2026/05/21/10