PYSEC-2026-406

Vulnerability from pysec - Published: 2026-06-29 11:50 - Updated: 2026-07-01 20:22
VLAI
Details

The mamba language model framework thru 2.2.6 is vulnerable to insecure deserialization (CWE-502) when loading pre-trained models from HuggingFace Hub. The MambaLMHeadModel.from_pretrained() method uses torch.load() to load the pytorch_model.bin weight file without enabling the security-restrictive weights_only=True parameter. This allows the deserialization of arbitrary Python objects via the pickle module. An attacker can exploit this by publishing a malicious model repository on HuggingFace Hub. When a victim loads a model from this repository, arbitrary code is executed on the victim's system in the context of the mamba process.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Impacted products
Name purl
mamba-ssm pkg:pypi/mamba-ssm
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "mamba-ssm",
        "purl": "pkg:pypi/mamba-ssm"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "2.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.1",
        "1.1.0",
        "1.1.1",
        "1.1.2",
        "1.1.3.post1",
        "1.1.4",
        "1.2.0",
        "1.2.0.post1",
        "1.2.1",
        "1.2.2",
        "2.0.0",
        "2.0.1",
        "2.0.2",
        "2.0.3",
        "2.0.4",
        "2.1.0",
        "2.2.0",
        "2.2.1",
        "2.2.2",
        "2.2.3.post2",
        "2.2.4",
        "2.2.5"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-31239",
    "GHSA-pq2f-x424-6fjm"
  ],
  "details": "The mamba language model framework thru 2.2.6 is vulnerable to insecure deserialization (CWE-502) when loading pre-trained models from HuggingFace Hub. The MambaLMHeadModel.from_pretrained() method uses torch.load() to load the pytorch_model.bin weight file without enabling the security-restrictive weights_only=True parameter. This allows the deserialization of arbitrary Python objects via the pickle module. An attacker can exploit this by publishing a malicious model repository on HuggingFace Hub. When a victim loads a model from this repository, arbitrary code is executed on the victim\u0027s system in the context of the mamba process.",
  "id": "PYSEC-2026-406",
  "modified": "2026-07-01T20:22:56.958502Z",
  "published": "2026-06-29T11:50:49.341783Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31239"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/state-spaces/mamba"
    },
    {
      "type": "WEB",
      "url": "https://www.notion.so/CVE-2026-31239-35d1e1393188810d9baedfbd8363f396"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/mamba-ssm"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-pq2f-x424-6fjm"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "mamba language model framework vulnerable to insecure deserialization when loading pre-trained models from HuggingFace Hub"
}



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