{
  "fix": "Mozilla Thunderbird (en-US) 149.0",
  "url": "https://patchblox.com/security/fix/windows-app/mozilla.thunderbird-149.0",
  "summary": "Mozilla Thunderbird (en-US) 149.0, released March 24, 2026, fixes 14 CVEs in Mozilla Thunderbird (en-US). None of them is reported as exploited. Patch Radar priority: Urgent. 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) 149.0",
  "released": "2026-03-24T00:00:00Z",
  "priority": "Urgent",
  "priorityTier": 2,
  "priorityReason": "Closes CVE-2026-4724, rated Critical",
  "supported": true,
  "cveCount": 14,
  "exploitedCveCount": 0,
  "kevCveCount": 0,
  "ransomwareCveCount": 0,
  "maxEpss": 0.00803,
  "maxCvss": 10,
  "appliesTo": [
    {
      "product": "Mozilla Thunderbird (en-US)",
      "productUrl": "https://patchblox.com/security/product/windows-app/mozilla-thunderbird-en-us",
      "fixedVersion": "149.0",
      "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-2026-4724",
      "url": "https://patchblox.com/security/cve/CVE-2026-4724",
      "title": "Undefined behavior in the Audio/Video component",
      "priority": "Urgent",
      "cvss": 9.1,
      "epss": 0.00507,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4729",
      "url": "https://patchblox.com/security/cve/CVE-2026-4729",
      "title": "Memory safety bugs fixed in Firefox 149 and Thunderbird 149",
      "priority": "Urgent",
      "cvss": 9.8,
      "epss": 0.00343,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4694",
      "url": "https://patchblox.com/security/cve/CVE-2026-4694",
      "title": "Incorrect boundary conditions, integer overflow in the Graphics component",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.2,
      "epss": 0.00803,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4689",
      "url": "https://patchblox.com/security/cve/CVE-2026-4689",
      "title": "Sandbox escape due to incorrect boundary conditions, integer overflow in the XPCOM component",
      "priority": "High",
      "severity": "Important",
      "cvss": 10,
      "epss": 0.00691,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4726",
      "url": "https://patchblox.com/security/cve/CVE-2026-4726",
      "title": "Denial-of-service in the XML component",
      "priority": "High",
      "cvss": 7.5,
      "epss": 0.00551,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4727",
      "url": "https://patchblox.com/security/cve/CVE-2026-4727",
      "title": "Denial-of-service in the Libraries component in NSS",
      "priority": "High",
      "cvss": 7.5,
      "epss": 0.00551,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4692",
      "url": "https://patchblox.com/security/cve/CVE-2026-4692",
      "title": "Sandbox escape in the Responsive Design Mode component",
      "priority": "High",
      "severity": "Important",
      "cvss": 10,
      "epss": 0.00506,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4718",
      "url": "https://patchblox.com/security/cve/CVE-2026-4718",
      "title": "Undefined behavior in the WebRTC: Signaling component",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.2,
      "epss": 0.00481,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4720",
      "url": "https://patchblox.com/security/cve/CVE-2026-4720",
      "title": "Memory safety bugs fixed in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149",
      "priority": "High",
      "severity": "Important",
      "cvss": 9.8,
      "epss": 0.0044,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4721",
      "url": "https://patchblox.com/security/cve/CVE-2026-4721",
      "title": "Memory safety bugs fixed in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149",
      "priority": "High",
      "severity": "Important",
      "cvss": 9.8,
      "epss": 0.0044,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4710",
      "url": "https://patchblox.com/security/cve/CVE-2026-4710",
      "title": "Incorrect boundary conditions in the Audio/Video component",
      "priority": "High",
      "severity": "Important",
      "cvss": 9.8,
      "epss": 0.00425,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4371",
      "url": "https://patchblox.com/security/cve/CVE-2026-4371",
      "title": "Out of bounds read in IMAP parsing",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.2,
      "epss": 0.00367,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-3889",
      "url": "https://patchblox.com/security/cve/CVE-2026-3889",
      "title": "Spoofing issue in Thunderbird",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.2,
      "epss": 0.00206,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-4728",
      "url": "https://patchblox.com/security/cve/CVE-2026-4728",
      "title": "Spoofing issue in the Privacy: Anti-Tracking component",
      "priority": "Routine",
      "cvss": 6.5,
      "epss": 0.00244,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    }
  ],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}