CVE-2026-4963Public exploitNetwork attack vector

Arbitrary code execution via dunder-check bypasses

Published Mar 27, 2026 · Updated Mar 27, 2026

Code injection in Hugging Face smolagents 1.25.0.dev0 allows remote attackers to execute arbitrary code through LocalPythonExecutor. evaluate_augassign reads and writes dunder attributes through raw getattr and setattr calls, while evaluate_call permits user-defined str and repr methods. Exploitation requires attacker-controlled Python, such as code generated from a malicious prompt, to reach the local executor; commands then run with the agent process's privileges.

CVSS severity6.3
Medium
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

Code injection in Hugging Face smolagents 1.25.0.dev0 allows remote attackers to execute arbitrary code through LocalPythonExecutor. evaluate_augassign reads and writes dunder attributes through raw getattr and setattr calls, while evaluate_call permits user-defined str and repr methods. Exploitation requires attacker-controlled Python, such as code generated from a malicious prompt, to reach the local executor; commands then run with the agent process's privileges.

The record

CVE
CVE-2026-4963
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
Hugging Face
Product
smolagents
Classifications
CWE-94, CWE-74, T1059.006
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 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?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.25.0.dev0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Hugging Face · smolagentsversion=1.25.0.dev0

Published CVSS scores

6.3VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
10.0NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
2.1VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
7.5VulDBAV:N/AC:L/Au:N/C:P/I:P/A:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-74Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
T1059.006Command and Scripting Interpreter: Python

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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