Arbitrary Code Injection Affecting smolagents package, versions [1.21.0,]
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-PYTHON-SMOLAGENTS-15812240
- published29 Mar 2026
- disclosed27 Mar 2026
- creditYLChen-007
Introduced: 27 Mar 2026
CVE-2026-4963 (opens in a new tab)How to fix?
There is no fixed version for smolagents.
Overview
smolagents is a 🤗 smolagents: a barebones library for agents. Agents write python code to call tools or orchestrate other agents.
Affected versions of this package are vulnerable to Arbitrary Code Injection through the LocalPythonExecutor in the local_python_executor.py component. An attacker can execute arbitrary code on the host by defining a class with a malicious __str__ or __repr__ method and then causing str() to be called on that object.