{
  "fix": "KB5007409",
  "url": "https://patchblox.com/security/fix/microsoft/kb5007409",
  "summary": "KB5007409, released November 9, 2021, fixes 3 CVEs across 5 products. One of them is being exploited (CVE-2021-42321); 1 on CISA KEV. Patch Radar priority: Patch now. The product is no longer supported.",
  "platform": "microsoft",
  "type": "kb",
  "releaseKind": "Security",
  "title": "November 2021 security update",
  "released": "2021-11-09T14:00:00Z",
  "priority": "Patch now",
  "priorityTier": 1,
  "priorityReason": "Closes CVE-2021-42321, exploited (CISA KEV, ransomware)",
  "supported": false,
  "cveCount": 3,
  "exploitedCveCount": 1,
  "kevCveCount": 1,
  "ransomwareCveCount": 1,
  "maxEpss": 0.93497,
  "maxCvss": 8.8,
  "vendorAdvisory": "https://support.microsoft.com/help/5007409",
  "appliesTo": [
    {
      "product": "Microsoft Exchange Server 2013 Cumulative Update 23",
      "productUrl": "https://patchblox.com/security/product/microsoft/microsoft-exchange-server-2013-cumulative-update-23",
      "fixedVersion": "",
      "supported": false
    },
    {
      "product": "Microsoft Exchange Server 2016 Cumulative Update 21",
      "productUrl": "https://patchblox.com/security/product/microsoft/microsoft-exchange-server-2016-cumulative-update-21",
      "fixedVersion": "",
      "supported": false
    },
    {
      "product": "Microsoft Exchange Server 2016 Cumulative Update 22",
      "productUrl": "https://patchblox.com/security/product/microsoft/microsoft-exchange-server-2016-cumulative-update-22",
      "fixedVersion": "",
      "supported": false
    },
    {
      "product": "Microsoft Exchange Server 2019 Cumulative Update 10",
      "productUrl": "https://patchblox.com/security/product/microsoft/microsoft-exchange-server-2019-cumulative-update-10",
      "fixedVersion": "",
      "supported": false
    },
    {
      "product": "Microsoft Exchange Server 2019 Cumulative Update 11",
      "productUrl": "https://patchblox.com/security/product/microsoft/microsoft-exchange-server-2019-cumulative-update-11",
      "fixedVersion": "",
      "supported": false
    }
  ],
  "cves": [
    {
      "cveId": "CVE-2021-42321",
      "url": "https://patchblox.com/security/cve/CVE-2021-42321",
      "title": "Microsoft Exchange Server Remote Code Execution Vulnerability",
      "component": "Microsoft Exchange Server",
      "impact": "Remote Code Execution",
      "priority": "Patch now",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.91737,
      "kev": true,
      "ransomware": true,
      "exploited": true,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-41349",
      "url": "https://patchblox.com/security/cve/CVE-2021-41349",
      "title": "Microsoft Exchange Server Spoofing Vulnerability",
      "component": "Microsoft Exchange Server",
      "impact": "Spoofing",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.93497,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-42305",
      "url": "https://patchblox.com/security/cve/CVE-2021-42305",
      "title": "Microsoft Exchange Server Spoofing Vulnerability",
      "component": "Microsoft Exchange Server",
      "impact": "Spoofing",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.0787,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    }
  ],
  "dataAsOf": "2026-11-07T06:34:28Z"
}