Tencent AI-Infra-Guard skill-scan Analysis Bypass via Excluded Python Bytecode

{
  "id": "b0d456134c0d761152f3133adf2038f90c72b46666f59308237d9e3ba8d63e2b",
  "url": "https://osv.dev/vulnerability/CVE-2026-84809",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Tencent AI-Infra-Guard skill-scan Analysis Bypass via Excluded Python Bytecode",
    "summary": "Tencent AI-Infra-Guard's skill-scan component excludes compiled Python bytecode files from analysis by hardcoding __pycache__ directories and .pyc/.pyo/.pyd extensions into skip lists across multiple scanning surfaces. Attackers can distribute skills with benign Python source files alongside malicious compiled bytecode that executes on import while the scanner reports a safe verdict, enabling code execution when operators install the skill.",
    "evidence": "osv:CVE-2026-84809",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-84809",
      "aliases": [
        "CVE-2026-84809"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/tencent/ai-infra-guard",
              "type": "GIT",
              "events": [
                {
                  "introduced": "e8931cc68001b66ad024fd87ef07394e9e96524a"
                },
                {
                  "fixed": "7e0f749e3c023e5c6ab7b32fe97b3f6f2e8aeb04"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "4.6.0"
                      },
                      {
                        "last_affected": "4.6.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandaloneSingleVersion"
                  },
                  {
                    "range": [
                      {
                        "fixed": "7e0f749e3c023e5c6ab7b32fe97b3f6f2e8aeb04"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.6.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-84809.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:21.805278958Z",
      "provider": "osv",
      "references": [
        "https://pypi.org",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84809.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-84809",
        "https://www.vulncheck.com/advisories/tencent-ai-infra-guard-skill-scan-analysis-bypass-via-excluded-python-bytecode",
        "https://github.com/Tencent/AI-Infra-Guard/issues/531",
        "https://github.com/Tencent/AI-Infra-Guard/commit/7e0f749e3c023e5c6ab7b32fe97b3f6f2e8aeb04",
        "https://github.com/Tencent/AI-Infra-Guard",
        "https://github.com/Tencent/AI-Infra-Guard/blob/v4.6.0/skill-scan/skill_scan/tools/dir/dir_actions.py",
        "https://github.com/Tencent/AI-Infra-Guard/blob/v4.6.0/skill-scan/skill_scan/utils/pre_scan.py"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-693"
        ],
        "cna_assigner": "VulnCheck",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "fixed": "4.5.2"
                  },
                  {
                    "last_affected": "0.2.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84809.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-84809",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 488238,
  "published_at": "2026-09-02T16:59:48.8+00:00"
}