{
  "cveId": "CVE-2026-81963",
  "url": "https://patchblox.com/security/cve/CVE-2026-81963",
  "summary": "CVE-2026-81963 is fixed in 10 products on 1 platform, first by KB5122880, released September 8, 2026. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on September 8, 2026. Patch Radar priority: Patch now.",
  "title": "Windows Update Stack Elevation of Privilege Vulnerability",
  "description": "\u003Cp\u003EImproper link resolution before file access (\u0027link following\u0027) in Windows Update Stack allows an authorized attacker to elevate privileges locally.\u003C/p\u003E",
  "published": "2026-09-08T07:00:00Z",
  "severity": "Important",
  "cvss": 7.8,
  "cwe": "Improper Link Resolution Before File Access (\u0027Link Following\u0027)",
  "epss": 0.00393,
  "epssPercentile": 0.33761,
  "priority": "Patch now",
  "priorityTier": 1,
  "exploited": true,
  "vendorExploited": true,
  "disclosed": false,
  "exploitabilityAssessment": "Exploitation Detected",
  "kev": {
    "added": "2026-09-08T00:00:00Z",
    "due": "2026-09-22T00:00:00Z",
    "ransomware": false,
    "requiredAction": "Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA\u2019s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA\u2019s \u201CForensics Triage Requirements\u201D (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset\u0027s internet exposure and ensuring adherence to BOD 26-04 patching guidelines."
  },
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-81963",
  "fixes": [
    {
      "platform": "microsoft",
      "product": "Windows 11 Version 23H2 for ARM64-based Systems",
      "fixedVersion": "22631.7582",
      "fix": "KB5122880",
      "url": "https://patchblox.com/security/fix/microsoft/kb5122880",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows 11 Version 23H2 for x64-based Systems",
      "fixedVersion": "22631.7582",
      "fix": "KB5122880",
      "url": "https://patchblox.com/security/fix/microsoft/kb5122880",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows 11 Version 24H2 for ARM64-based Systems",
      "fixedVersion": "",
      "fix": "KB5124008",
      "url": "https://patchblox.com/security/fix/microsoft/kb5124008",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows 11 Version 24H2 for x64-based Systems",
      "fixedVersion": "",
      "fix": "KB5124008",
      "url": "https://patchblox.com/security/fix/microsoft/kb5124008",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows 11 Version 25H2 for ARM64-based Systems",
      "fixedVersion": "",
      "fix": "KB5124008",
      "url": "https://patchblox.com/security/fix/microsoft/kb5124008",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows 11 Version 25H2 for x64-based Systems",
      "fixedVersion": "",
      "fix": "KB5124008",
      "url": "https://patchblox.com/security/fix/microsoft/kb5124008",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows 11 Version 26H1 for ARM64-based Systems",
      "fixedVersion": "28000.2954",
      "fix": "KB5124012",
      "url": "https://patchblox.com/security/fix/microsoft/kb5124012",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows 11 version 26H1 for x64-based Systems",
      "fixedVersion": "28000.2954",
      "fix": "KB5124012",
      "url": "https://patchblox.com/security/fix/microsoft/kb5124012",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows Server 2025",
      "fixedVersion": "26100.33438",
      "fix": "KB5122871",
      "url": "https://patchblox.com/security/fix/microsoft/kb5122871",
      "released": "2026-09-08T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Windows Server 2025 (Server Core installation)",
      "fixedVersion": "26100.33438",
      "fix": "KB5122871",
      "url": "https://patchblox.com/security/fix/microsoft/kb5122871",
      "released": "2026-09-08T00:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}