CVE-2026-48207Network attack vector

Type restriction bypass during reduce-state restoration

Published May 21, 2026 · Updated May 21, 2026

Insecure deserialization in Apache Fory PyFory 0.13.0 through 0.17.0 allows remote attackers to bypass application type restrictions. ReduceSerializer restores reduce state and resolves global names without consistently invoking configured DeserializationPolicy validation hooks. Exploitation requires Python-native mode with strict mode disabled, attacker-controlled serialized data, and reliance on a custom policy; denied classes, functions, or module attributes can then be reconstructed.

CVSS severity9.8
Critical
EPSS probability0.57%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insecure deserialization in Apache Fory PyFory 0.13.0 through 0.17.0 allows remote attackers to bypass application type restrictions. ReduceSerializer restores reduce state and resolves global names without consistently invoking configured DeserializationPolicy validation hooks. Exploitation requires Python-native mode with strict mode disabled, attacker-controlled serialized data, and reliance on a custom policy; denied classes, functions, or module attributes can then be reconstructed.

The record

CVE
CVE-2026-48207
Published
May 21, 2026
Updated
May 21, 2026
Vendor
The Apache Software Foundation
Product
Apache Fory
Classifications
CWE-502, CAPEC-586
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 21, 2026CVE publishedPublication date reported by the CVE source.
  2. May 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=0.13.0 <1.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Foryversion=0.13.0 <1.0.0

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-502Deserialization of Untrusted Data
CAPEC-586Object Injection

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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