{
  "id": "CVE-2021-43226",
  "url": "https://spydr.io/cve/CVE-2021-43226",
  "published": "2021-12-15T15:15:09.737Z",
  "modified": "2026-08-22T04:16:54.773Z",
  "score": 7.8,
  "severity": "high",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "score_source": "NVD",
  "epss": 0.03098,
  "epss_percentile": 0.87313,
  "exploited": true,
  "kev": {
    "added": "2025-10-06",
    "due": "2025-10-27",
    "action": "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.",
    "ransomware": "Known",
    "name": "Microsoft Windows Privilege Escalation Vulnerability",
    "notes": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-43226 ; https://nvd.nist.gov/vuln/detail/CVE-2021-43226"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "Microsoft"
  ],
  "products": [
    "Microsoft Windows 10 Version 1809",
    "Microsoft Windows Server 2019",
    "Microsoft Windows Server 2019 (Server Core installation)",
    "Microsoft Windows 10 Version 1909",
    "Microsoft Windows 10 Version 21H1",
    "Microsoft Windows Server 2022",
    "Microsoft Windows 10 Version 2004",
    "Microsoft Windows Server version 2004",
    "Microsoft Windows 10 Version 20H2",
    "Microsoft Windows Server version 20H2",
    "Microsoft Windows 11 version 21H2",
    "Microsoft Windows 10 Version 21H2",
    "Microsoft Windows 10 Version 1507",
    "Microsoft Windows 10 Version 1607",
    "Microsoft Windows Server 2016",
    "Microsoft Windows Server 2016 (Server Core installation)",
    "Microsoft Windows 7",
    "Microsoft Windows 7 Service Pack 1",
    "Microsoft Windows 8.1",
    "Microsoft Windows Server 2008 Service Pack 2"
  ],
  "cwes": [],
  "description": "Windows Common Log File System Driver Elevation of Privilege Vulnerability",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 7.8,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-43226",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-43226",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-43226",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}