ForyApplication · Apache
CVE-2026-48207
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedDeserialization 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceApache Fory PyFory's ReduceSerializer contains a deserialization bypass that allows attacker-controlled data to bypass DeserializationPolicy validation hooks during reduce-state restoration and global-name resolution. When Python-native mode is used with strict mode disabled and the application relies on DeserializationPolicy for security, attackers can potentially deserialize unsafe classes, functions, or module attributes to achieve code execution.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
ForyApplication
>= 0.13.0, < 1.0.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the installed PyFory versionRun `pip show pyfory` or `pip list | grep -i fory` to retrieve the installed version of Apache Fory or PyFory packageAffected if The installed version is >= 0.13.0 and < 1.0.0
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Determine if Python-native deserialization mode is activeInspect your application code or configuration for settings that enable Python-native mode in PyFory's deserialization, such as a mode flag or configuration parameter that selects native Python object reconstructionAffected if Python-native mode is enabled in the deserialization configuration
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Verify whether strict mode is disabledExamine your deserialization configuration or startup settings for the DeserializationPolicy strict mode setting; look for flags or parameters that control strict validationAffected if Strict mode is disabled or not explicitly enabled in the deserialization policy configuration
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Identify ReduceSerializer usage in your codeSearch your codebase for usage of ReduceSerializer class or method calls related to reduce-state restoration and global-name resolution during deserializationAffected if ReduceSerializer is being used to deserialize data in the affected configuration (Python-native mode with strict mode disabled)
You are affected if your Apache Fory version is between 0.13.0 and 1.0.0 AND you are using Python-native deserialization mode with strict mode disabled while employing ReduceSerializer for reduce-state restoration.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped1.0.0
Upgrade Apache Fory to version 1.0.0 or later, which enforces DeserializationPolicy validation for the affected ReduceSerializer paths. Also review and enable strict mode if currently disabled.
1.0.0
- Identify all systems running Apache Fory versions 0.13.0 through 0.99.x that use PyFory Python-native mode
- Stop any services currently using the vulnerable PyFory library
- Upgrade Apache Fory to version 1.0.0 or later using the appropriate installation method (pip, source, or package manager)
- Restart the services with the upgraded Fory version
- Verify the upgrade was successful and confirm DeserializationPolicy validation is now enforced for ReduceSerializer paths
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Fory
Scoped from the published advisory
- Consultation4.0 h
- Implementation4.0 h
- Testing8.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,504.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-48207 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-48207 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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