Vulnerabilities in pkg:pypi/pyfory

PACKAGE
Advisory Identifier: GHSA-m5gw-83w2-7749
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Advisory Summary

CVE-2026-48207 is a CRITICAL (CVSS 9.8) apache fory pyfory deserialization of vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Pyfory libraries in the PyPI ecosystem. The issue involves apache fory pyfory deserialization of untrusted data. Remediation is available by upgrading affected packages to version 1.0.0.

2 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:pypi/pyfory

2 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:pypi/pyfory. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-m5gw-83w2-7749 CVE-2026-48207 CRITICAL Apache Fory PyFory Deserialization of Untrusted Data
GHSA-538v-3wq9-4h3r CVE-2025-61622 CRITICAL Apache Pyfory python is vulnerable to deserialization of untrusted data

CVE-2026-48207 at a Glance

CVE Identifier CVE-2026-48207
GHSA Identifier GHSA-m5gw-83w2-7749
Severity CRITICAL
CVSS v3.1 Base Score 9.8
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Pyfory
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 9.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-48207

To remediate this vulnerability, upgrade all affected Pyfory dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

pyfory fixed: 1.0.0 
pip install pyfory>=1.0.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show pyfory

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-48207, inspect your installed packages using pip:

pip show pyfory

Analyze the terminal output to locate any version of Pyfory in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.0), your application is affected.

Note: The pip show pyfory command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Pyfory, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

Fory 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.

CVE-2026-48207 Affected Pyfory Versions

1 component(s)
Fixed Versions:
1.0.0
Product / Package Ecosystem Affected Versions Fixed Version
pyfory
pypi/pyfory
PyPI
≥ 0.13.0
< 1.0.0
1.0.0

References

NVD — CVE-2026-48207 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-48207
Pyfory Security Information SECURITY
https://fory.apache.org/security/#cve-2026-48207-pyfory-reduceserializer-deserializationpolicy-bypass
Pyfory Source Repository REPOSITORY
https://github.com/apache/fory
Pyfory Security Information SECURITY
http://www.openwall.com/lists/oss-security/2026/05/21/10

Frequently Asked Questions

What is CVE-2026-48207?
CVE-2026-48207 is a security vulnerability in Pyfory involving Apache Fory PyFory Deserialization of Untrusted Data under CWE-502: Deserialization of Untrusted Data.
Which Pyfory versions are affected?
Affected versions include releases prior to 1.0.0 across affected packages: pyfory.
What version fixes CVE-2026-48207?
Upgrading to 1.0.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is pyfory affected?
Yes, pyfory is affected in releases prior to 1.0.0. Upgrade your dependency to 1.0.0 or later.
What is the CVSS score of CVE-2026-48207?
CVE-2026-48207 has a CVSS v3.1 base score of 9.8 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-48207?
CVE-2026-48207 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check PyPI dependencies for CVE-2026-48207?
Run the dependency tree command: 'pip show pyfory'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m5gw-83w2-7749",
  "modified" : "2026-06-30T21:44:43Z",
  "published" : "2026-05-21T18:33:09Z",
  "aliases" : [ "CVE-2026-48207" ],
  "summary" : "Apache Fory PyFory Deserialization of Untrusted Data ",
  "details" : "Fory 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.\n\nThis issue affects Apache Fory: from before 1.0.0.\n\nMitigation: 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.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "pyfory"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.13.0"
      }, {
        "fixed" : "1.0.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-48207"
  }, {
    "type" : "WEB",
    "url" : "https://fory.apache.org/security/#cve-2026-48207-pyfory-reduceserializer-deserializationpolicy-bypass"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/apache/fory"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2026/05/21/10"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-30T21:44:43Z",
    "nvd_published_at" : "2026-05-21T17:16:21Z"
  }
}