Sandbox escape in smolagents Local Python execution environment via dunder attributes

{
  "id": "4fb749683f4dd8195d5d48fce75d02940e6299692f60b869ca64fb99a2c1fc5b",
  "url": "https://osv.dev/vulnerability/CVE-2025-9959",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Sandbox escape in smolagents Local Python execution environment via dunder attributes",
    "summary": "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.",
    "evidence": "osv:CVE-2025-9959",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2025-9959",
      "aliases": [
        "CVE-2025-9959"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/huggingface/smolagents",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "420eaebf2b7ebc1461b5b669f8af1bef1b9bd00e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.21.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.0.0",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-9959.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:25.668357979Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/9xxx/CVE-2025-9959.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-9959",
        "https://research.jfrog.com/vulnerabilities/smolagents-local-python-sandbox-escape-jfsa-2025-001434277/",
        "https://github.com/huggingface/smolagents/pull/1551",
        "https://pypi.org/project/pip"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-94"
        ],
        "cna_assigner": "JFROG",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/9xxx/CVE-2025-9959.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-9959",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492411,
  "published_at": "2025-09-03T16:53:46.304+00:00"
}