CVE-2025-9959

Status: DeferredHigh (7.6)—

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.

CVSS

Version: 3.1
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L
Base score: 7.6

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 0.31%
Percentile among all scored CVEs: 22
Score date: 10/5/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

ExploitationT1203 Exploitation for Client Executionexecution85 %
Primary impactT1059 Command and Scripting Interpreterexecution80 %
Secondary impactT1565 Data Manipulationimpact60 %

AV:N/UI:R requiere interacción del usuario (Prompt Injection) para engañar al agente. Permite ejecución de código Python mediante escape del sandbox. La manipulación de atributos dunder y los datos resultantes sustentan T1565 como impacto secundario.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Restrict Web-Based Content Restrict File and Directory Permissions Privileged Account Management Remote Data Storage Network Segmentation Limit Software Installation

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Huggingface — Smolagents^AI

CWEs

CWE-94

References

Raw JSON (NVD)

Show

{
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  "published": "2025-09-03T17:15:35.737",
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      "url": "https://github.com/huggingface/smolagents/pull/1551",
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    }
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  "lastModified": "2026-09-26T00:10:00.127",
  "sourceIdentifier": "reefs@jfrog.com"
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