{
  "cveId": "CVE-2021-26411",
  "url": "https://patchblox.com/security/cve/CVE-2021-26411",
  "summary": "CVE-2021-26411 is fixed in 56 products on 1 platform, first by KB5000803, released March 9, 2021. It is being exploited: CISA added it to the Known Exploited Vulnerabilities catalog on November 3, 2021, with known ransomware use. Patch Radar priority: Patch now.",
  "title": "Internet Explorer Memory Corruption Vulnerability",
  "description": "",
  "published": "2021-03-09T14:00:00Z",
  "severity": "Critical",
  "cvss": 8.8,
  "epss": 0.81667,
  "epssPercentile": 0.99645,
  "priority": "Patch now",
  "priorityTier": 1,
  "exploited": true,
  "vendorExploited": true,
  "disclosed": true,
  "exploitabilityAssessment": "Exploitation Detected",
  "kev": {
    "added": "2021-11-03T00:00:00Z",
    "due": "2021-11-17T00:00:00Z",
    "ransomware": true,
    "requiredAction": "Apply updates per vendor instructions."
  },
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26411",
  "fixes": [
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1607 for 32-bit Systems",
      "fixedVersion": "14393.4283",
      "fix": "KB5000803",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000803",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1607 for x64-based Systems",
      "fixedVersion": "14393.4283",
      "fix": "KB5000803",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000803",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1803 for 32-bit Systems",
      "fixedVersion": "17134.2087",
      "fix": "KB5000809",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000809",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1803 for ARM64-based Systems",
      "fixedVersion": "17134.2087",
      "fix": "KB5000809",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000809",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1803 for x64-based Systems",
      "fixedVersion": "17134.2087",
      "fix": "KB5000809",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000809",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1809 for 32-bit Systems",
      "fixedVersion": "17763.1817",
      "fix": "KB5000822",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000822",
      "released": "2021-03-09T00:00:00Z"
    },
    {
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      "product": "Internet Explorer 11 on Windows 10 Version 1809 for ARM64-based Systems",
      "fixedVersion": "17763.1817",
      "fix": "KB5000822",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000822",
      "released": "2021-03-09T00:00:00Z"
    },
    {
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      "fixedVersion": "17763.1817",
      "fix": "KB5000822",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000822",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1903 for ARM64-based Systems",
      "fixedVersion": "18363.1440",
      "fix": "KB5000808",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000808",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1903 for x64-based Systems",
      "fixedVersion": "18363.1440",
      "fix": "KB5000808",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000808",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
      "product": "Internet Explorer 11 on Windows 10 Version 1909 for 32-bit Systems",
      "fixedVersion": "18363.1440",
      "fix": "KB5000808",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000808",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
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      "url": "https://patchblox.com/security/fix/microsoft/kb5000808",
      "released": "2021-03-09T00:00:00Z"
    },
    {
      "platform": "microsoft",
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      "url": "https://patchblox.com/security/fix/microsoft/kb5000808",
      "released": "2021-03-09T00:00:00Z"
    },
    {
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      "fixedVersion": "",
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      "released": "2021-03-09T00:00:00Z"
    },
    {
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      "fixedVersion": "",
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      "released": "2021-03-09T00:00:00Z"
    },
    {
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      "fix": "KB5000807",
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      "released": "2021-03-09T00:00:00Z"
    },
    {
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      "released": "2021-03-09T00:00:00Z"
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      "fixedVersion": "",
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      "released": "2021-03-09T14:00:00Z"
    },
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      "released": "2021-03-09T14:00:00Z"
    },
    {
      "platform": "microsoft",
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      "fixedVersion": "",
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      "url": "https://patchblox.com/security/fix/microsoft/kb5000841",
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    },
    {
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    {
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      "fixedVersion": "",
      "fix": "KB5000848",
      "url": "https://patchblox.com/security/fix/microsoft/kb5000848",
      "released": "2021-03-09T14:00:00Z"
    },
    {
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      "url": "https://patchblox.com/security/fix/microsoft/kb5000847",
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    {
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    },
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      "released": "2021-03-09T00:00:00Z"
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  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}