CVE-2025-9959

Sandbox escape in smolagents Local Python execution environment via dunder attributes

State: Published
Severity: 7.6 High
Published: Sep 3, 2025
Updated: Sep 3, 2025
Reserved: Sep 3, 2025

Description

Incomplete validation of dunder attributes allows an attacker to escape from the Local Python execution environment sandbox, enforced by smolagents. The attack requires a Prompt Injection in order to trick the agent to create malicious code.

Scores

CVSS	Score	Vector	Source
3.1	7.6 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L	JFROG

Weaknesses

CWE-94 Improper Control of Generation of Code ('Code Injection')

Affected Products

Product	Versions
smolagents	before 1.21.0Affected

References

https://research.jfrog.com/vulnerabilities/smolagents-local-python-sandbox-escape-jfsa-2025-001434277/third-party-advisory
https://github.com/huggingface/smolagents/pull/1551patch

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