PYSEC-2026-4164

Vulnerability from pysec - Published: 2026-10-01 16:38 - Updated: 2026-10-01 17:10
VLAI
Details

sentence-transformers contains a security control bypass vulnerability that allows attackers to achieve arbitrary code execution by exploiting a logic flaw in the import_module_class helper within sentence_transformers/util/misc.py, where the guard condition includes an 'or os.path.exists(model_name_or_path)' clause that satisfies the trust gate whenever the supplied path exists on the local filesystem, regardless of the trust_remote_code=False argument. Attackers who can control or influence the contents of a model directory on disk can place malicious Python files such as modeling_*.py referenced via modules.json, causing the code to execute at import time when an application loads the model with SentenceTransformer(path, trust_remote_code=False), bypassing the documented security contract and achieving code execution within the loading process.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3 (Critical)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Impacted products
Name purl
sentence-transformers pkg:pypi/sentence-transformers
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "sentence-transformers",
        "purl": "pkg:pypi/sentence-transformers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.6.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1.0",
        "0.2.0",
        "0.2.1",
        "0.2.2",
        "0.2.3",
        "0.2.4",
        "0.2.4.1",
        "0.2.5",
        "0.2.5.1",
        "0.2.6",
        "0.2.6.1",
        "0.2.6.2",
        "0.3.0",
        "0.3.1",
        "0.3.2",
        "0.3.3",
        "0.3.4",
        "0.3.5",
        "0.3.5.1",
        "0.3.6",
        "0.3.7",
        "0.3.7.1",
        "0.3.7.2",
        "0.3.8",
        "0.3.9",
        "0.4.0",
        "0.4.1",
        "0.4.1.1",
        "0.4.1.2",
        "1.0.0",
        "1.0.1",
        "1.0.2",
        "1.0.3",
        "1.0.4",
        "1.1.0",
        "1.1.1",
        "1.2.0",
        "1.2.1",
        "2.0.0",
        "2.1.0",
        "2.2.0",
        "2.2.1",
        "2.2.2",
        "2.3.0",
        "2.3.1",
        "2.4.0",
        "2.5.0",
        "2.5.1",
        "2.6.0",
        "2.6.1",
        "2.7.0",
        "3.0.0",
        "3.0.1",
        "3.1.0",
        "3.1.1",
        "3.2.0",
        "3.2.1",
        "3.3.0",
        "3.3.1",
        "3.4.0",
        "3.4.1",
        "4.0.0",
        "4.0.1",
        "4.0.2",
        "4.1.0",
        "5.0.0",
        "5.1.0",
        "5.1.1",
        "5.1.2",
        "5.2.0",
        "5.2.1",
        "5.2.2",
        "5.2.3",
        "5.3.0",
        "5.4.0",
        "5.4.1",
        "5.5.0",
        "5.5.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-68770",
    "GHSA-jhr6-gm9c-rqjv"
  ],
  "details": "sentence-transformers contains a security control bypass vulnerability that allows attackers to achieve arbitrary code execution by exploiting a logic flaw in the import_module_class helper within sentence_transformers/util/misc.py, where the guard condition includes an \u0027or os.path.exists(model_name_or_path)\u0027 clause that satisfies the trust gate whenever the supplied path exists on the local filesystem, regardless of the trust_remote_code=False argument. Attackers who can control or influence the contents of a model directory on disk can place malicious Python files such as modeling_*.py referenced via modules.json, causing the code to execute at import time when an application loads the model with SentenceTransformer(path, trust_remote_code=False), bypassing the documented security contract and achieving code execution within the loading process.",
  "id": "PYSEC-2026-4164",
  "modified": "2026-10-01T17:10:43.456495Z",
  "published": "2026-10-01T16:38:29.083815Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68770"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/sentence-transformers/issues/3801"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/sentence-transformers/pull/3807"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/sentence-transformers/pull/3935"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/sentence-transformers/commit/626eb602b088878a8173bcab69225f68411b99e1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/sentence-transformers/commit/ae1acc3fb2aa2004577b297eb4a915ce7a03316a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/huggingface/sentence-transformers"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/sentence-transformers/releases/tag/v5.6.0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/sentence-transformers/releases/tag/v6.0.0"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/sentence-transformers-arbitrary-code-execution-on-local-model-load-despite-trust-remote-code-false"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/sentence-transformers"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-jhr6-gm9c-rqjv"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "sentence-transformers local model loading bypasses trust_remote_code and executes custom Python"
}



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