{
  "fix": "Mozilla Thunderbird (en-US) 91.2.0",
  "url": "https://patchblox.com/security/fix/windows-app/mozilla.thunderbird-91.2.0",
  "summary": "Mozilla Thunderbird (en-US) 91.2.0, released October 4, 2021, fixes 6 CVEs in Mozilla Thunderbird (en-US). None of them is reported as exploited. Patch Radar priority: High. The latest Mozilla Thunderbird (en-US) is 159.0, which also fixes every one of these CVEs.",
  "platform": "windows-app",
  "type": "app-version",
  "title": "Mozilla Thunderbird (en-US) 91.2.0",
  "released": "2021-10-04T00:00:00Z",
  "priority": "High",
  "priorityTier": 3,
  "priorityReason": "Closes CVE-2021-38496, high severity",
  "supported": true,
  "cveCount": 6,
  "exploitedCveCount": 0,
  "kevCveCount": 0,
  "ransomwareCveCount": 0,
  "maxEpss": 0.01659,
  "maxCvss": 8.8,
  "appliesTo": [
    {
      "product": "Mozilla Thunderbird (en-US)",
      "productUrl": "https://patchblox.com/security/product/windows-app/mozilla-thunderbird-en-us",
      "fixedVersion": "91.2.0",
      "latestVersion": "159.0",
      "supported": true
    }
  ],
  "supersededBy": {
    "product": "Mozilla Thunderbird (en-US)",
    "latestVersion": "159.0",
    "productUrl": "https://patchblox.com/security/product/windows-app/mozilla-thunderbird-en-us"
  },
  "cves": [
    {
      "cveId": "CVE-2021-38496",
      "url": "https://patchblox.com/security/cve/CVE-2021-38496",
      "title": "Mozilla Firefox ESR and 3 others: During operations on MessageTasks, a task may have been removed while it was still scheduled, resulting\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01659,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-38498",
      "url": "https://patchblox.com/security/cve/CVE-2021-38498",
      "title": "Mozilla Firefox ESR and 3 others: During process shutdown, a document could have caused a use-after-free of a languages service object,\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 7.5,
      "epss": 0.01467,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-38500",
      "url": "https://patchblox.com/security/cve/CVE-2021-38500",
      "title": "Mozilla Firefox ESR and 3 others: Mozilla developers reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1.",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01273,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-38502",
      "url": "https://patchblox.com/security/cve/CVE-2021-38502",
      "title": "Mozilla Thunderbird and 1 other: Thunderbird ignored the configuration to require STARTTLS security for an SMTP connection.",
      "priority": "High",
      "severity": "Important",
      "cvss": 7.5,
      "epss": 0.01101,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-38501",
      "url": "https://patchblox.com/security/cve/CVE-2021-38501",
      "title": "Mozilla Firefox ESR and 3 others: Mozilla developers reported memory safety bugs present in Firefox 92 and Firefox ESR 91.1.",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01048,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-38497",
      "url": "https://patchblox.com/security/cve/CVE-2021-38497",
      "title": "Mozilla Firefox ESR and 3 others: Through use of reportValidity() and window.open(), a plain-text validation message could have been overlaid\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.00591,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    }
  ],
  "dataAsOf": "2026-11-10T01:44:33Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}