CVE-2026-4963
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 · uneditedA weakness has been identified in huggingface smolagents 1.25.0.dev0. This affects the function evaluate_augassign/evaluate_call/evaluate_with of the file src/smolagents/local_python_executor.py of the component Incomplete Fix CVE-2025-9959. This manipulation causes code injection. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
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 · moderate confidenceA code injection vulnerability exists in huggingface smolagents 1.25.0.dev0 within the local_python_executor.py component. Specifically, the functions evaluate_augassign, evaluate_call, and evaluate_with contain insufficient validation that allows an attacker to inject and execute arbitrary code. This vulnerability is an incomplete fix for the previously disclosed CVE-2025-9959.
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= 1.25.0CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/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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Check installed smolagents versionRun 'pip show smolagents' or 'pip list | grep smolagents' to identify the installed versionAffected if The installed version is exactly 1.25.0
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Locate local_python_executor.pySearch for the file local_python_executor.py in the smolagents package installation directory, typically found in the agent directoryAffected if The file exists and is part of the installed smolagents package
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Verify vulnerable functions existOpen local_python_executor.py and search for the functions evaluate_augassign, evaluate_call, and evaluate_withAffected if These three functions are present in the file, indicating the vulnerable code path exists
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Confirm code execution feature is enabledCheck agent configuration or code that imports and uses CodeAgent or local_python_executor for code execution capabilitiesAffected if The application uses CodeAgent or directly imports and invokes local_python_executor for executing user-provided code
A user is affected if they have smolagents version 1.25.0 installed AND use the local_python_executor for code execution, as the vulnerable functions evaluate_augassign, evaluate_call, and evaluate_with contain insufficient validation.
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.
From vendor dataImplement complete input sanitization and validation in the code execution functions, or migrate to a sandboxed code execution environment that restricts dangerous operations.
- Consultation4.0 h
- Implementation12.0 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 $7,808.
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Free · runs locallyCheck whether your project pulls in CVE-2026-4963 — 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-2026-4963 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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