{
  "fix": "Mozilla Thunderbird (cs) 154.0",
  "url": "https://patchblox.com/security/fix/windows-app/mozilla.thunderbird.cs-154.0",
  "summary": "Mozilla Thunderbird (cs) 154.0, released August 18, 2026, fixes 56 CVEs in Mozilla Thunderbird (cs). None of them is reported as exploited. Patch Radar priority: Urgent. The latest Mozilla Thunderbird (cs) is 159.0, which also fixes every one of these CVEs.",
  "platform": "windows-app",
  "type": "app-version",
  "title": "Mozilla Thunderbird (cs) 154.0",
  "released": "2026-08-18T00:00:00Z",
  "priority": "Urgent",
  "priorityTier": 2,
  "priorityReason": "Closes CVE-2026-74943, rated Critical",
  "supported": true,
  "cveCount": 56,
  "exploitedCveCount": 0,
  "kevCveCount": 0,
  "ransomwareCveCount": 0,
  "maxEpss": 0.00961,
  "maxCvss": 10,
  "appliesTo": [
    {
      "product": "Mozilla Thunderbird (cs)",
      "productUrl": "https://patchblox.com/security/product/windows-app/mozilla-thunderbird-cs",
      "fixedVersion": "154.0",
      "latestVersion": "159.0",
      "supported": true
    }
  ],
  "supersededBy": {
    "product": "Mozilla Thunderbird (cs)",
    "latestVersion": "159.0",
    "productUrl": "https://patchblox.com/security/product/windows-app/mozilla-thunderbird-cs"
  },
  "cves": [
    {
      "cveId": "CVE-2026-74943",
      "url": "https://patchblox.com/security/cve/CVE-2026-74943",
      "title": "Use-after-free in the Graphics: ImageLib component",
      "priority": "Urgent",
      "severity": "critical",
      "cvss": 9.8,
      "epss": 0.00961,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74964",
      "url": "https://patchblox.com/security/cve/CVE-2026-74964",
      "title": "Integer overflow in the Graphics component",
      "priority": "Urgent",
      "severity": "critical",
      "cvss": 9.8,
      "epss": 0.00595,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74989",
      "url": "https://patchblox.com/security/cve/CVE-2026-74989",
      "title": "Internally found bugs fixed in Thunderbird 154",
      "priority": "Urgent",
      "cvss": 9.8,
      "epss": 0.0057,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74986",
      "url": "https://patchblox.com/security/cve/CVE-2026-74986",
      "title": "Site isolation issue in the CSS Parsing and Computation component",
      "priority": "Urgent",
      "cvss": 9.1,
      "epss": 0.00555,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74985",
      "url": "https://patchblox.com/security/cve/CVE-2026-74985",
      "title": "Privilege escalation in the Enterprise Policies component",
      "priority": "Urgent",
      "cvss": 9.8,
      "epss": 0.00527,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74956",
      "url": "https://patchblox.com/security/cve/CVE-2026-74956",
      "title": "Same-origin policy bypass in the DOM: Service Workers component",
      "priority": "Urgent",
      "cvss": 9.1,
      "epss": 0.00498,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-75874",
      "url": "https://patchblox.com/security/cve/CVE-2026-75874",
      "title": "Sandbox escape in the Remote Settings Client component",
      "priority": "Urgent",
      "severity": "critical",
      "cvss": 10,
      "epss": 0.00455,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74961",
      "url": "https://patchblox.com/security/cve/CVE-2026-74961",
      "title": "Side-channel in the Web Audio component",
      "priority": "Urgent",
      "cvss": 9.1,
      "epss": 0.00443,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74940",
      "url": "https://patchblox.com/security/cve/CVE-2026-74940",
      "title": "Use-after-free in the Graphics: Text component",
      "priority": "Urgent",
      "severity": "critical",
      "cvss": 9.8,
      "epss": 0.00412,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74936",
      "url": "https://patchblox.com/security/cve/CVE-2026-74936",
      "title": "Use-after-free in the JavaScript: WebAssembly component",
      "priority": "Urgent",
      "severity": "critical",
      "cvss": 9.8,
      "epss": 0.00403,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74944",
      "url": "https://patchblox.com/security/cve/CVE-2026-74944",
      "title": "Use-after-free in the DOM: Core \u0026 HTML component",
      "priority": "Urgent",
      "severity": "critical",
      "cvss": 9.8,
      "epss": 0.00403,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74959",
      "url": "https://patchblox.com/security/cve/CVE-2026-74959",
      "title": "Mitigation bypass in the Storage: Cache API component",
      "priority": "Urgent",
      "severity": "critical",
      "cvss": 9.1,
      "epss": 0.00342,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74979",
      "url": "https://patchblox.com/security/cve/CVE-2026-74979",
      "title": "Mitigation bypass in the Add-ons Manager component",
      "priority": "Urgent",
      "cvss": 9.8,
      "epss": 0.00306,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74945",
      "url": "https://patchblox.com/security/cve/CVE-2026-74945",
      "title": "Information disclosure in the Graphics: Text component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.0071,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74988",
      "url": "https://patchblox.com/security/cve/CVE-2026-74988",
      "title": "Internally found bugs fixed in Thunderbird ESR 153.1 and Thunderbird 154",
      "priority": "High",
      "severity": "important",
      "cvss": 9.8,
      "epss": 0.00609,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74977",
      "url": "https://patchblox.com/security/cve/CVE-2026-74977",
      "title": "Integer overflow in the Graphics component",
      "priority": "High",
      "cvss": 7.5,
      "epss": 0.006,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74990",
      "url": "https://patchblox.com/security/cve/CVE-2026-74990",
      "title": "Internally found bugs fixed in Thunderbird ESR 140.14, Thunderbird ESR 153.1 and Thunderbird 154",
      "priority": "High",
      "severity": "important",
      "cvss": 9.8,
      "epss": 0.00534,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74982",
      "url": "https://patchblox.com/security/cve/CVE-2026-74982",
      "title": "Denial-of-service in the Widget component",
      "priority": "High",
      "cvss": 7.5,
      "epss": 0.00534,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74987",
      "url": "https://patchblox.com/security/cve/CVE-2026-74987",
      "title": "Internally found bugs fixed in Thunderbird ESR 140.14, Thunderbird ESR 153.1 and Thunderbird 154",
      "priority": "High",
      "severity": "important",
      "cvss": 9.8,
      "epss": 0.00523,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74958",
      "url": "https://patchblox.com/security/cve/CVE-2026-74958",
      "title": "Information disclosure in the WebRTC component",
      "priority": "High",
      "cvss": 7.5,
      "epss": 0.00452,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74947",
      "url": "https://patchblox.com/security/cve/CVE-2026-74947",
      "title": "Privilege escalation due to invalid pointer in the Graphics component",
      "priority": "High",
      "cvss": 8.8,
      "epss": 0.00449,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74938",
      "url": "https://patchblox.com/security/cve/CVE-2026-74938",
      "title": "Mitigation bypass in the JavaScript: GC component",
      "priority": "High",
      "severity": "important",
      "cvss": 9.1,
      "epss": 0.00442,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74954",
      "url": "https://patchblox.com/security/cve/CVE-2026-74954",
      "title": "Information disclosure due to side-channel in the Storage: Cache API component",
      "priority": "High",
      "cvss": 7.5,
      "epss": 0.00439,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74966",
      "url": "https://patchblox.com/security/cve/CVE-2026-74966",
      "title": "Information disclosure in the Form Autofill component",
      "priority": "High",
      "cvss": 7.5,
      "epss": 0.00439,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74937",
      "url": "https://patchblox.com/security/cve/CVE-2026-74937",
      "title": "Use-after-free in the JavaScript: GC component",
      "priority": "High",
      "cvss": 8.8,
      "epss": 0.00436,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74950",
      "url": "https://patchblox.com/security/cve/CVE-2026-74950",
      "title": "Privilege escalation in the Downloads API component",
      "priority": "High",
      "severity": "important",
      "cvss": 8.8,
      "epss": 0.00415,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74952",
      "url": "https://patchblox.com/security/cve/CVE-2026-74952",
      "title": "Privilege escalation in the Application Update component",
      "priority": "High",
      "cvss": 8.8,
      "epss": 0.00415,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74955",
      "url": "https://patchblox.com/security/cve/CVE-2026-74955",
      "title": "Privilege escalation in the Request Handling component",
      "priority": "High",
      "cvss": 8.8,
      "epss": 0.00415,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74969",
      "url": "https://patchblox.com/security/cve/CVE-2026-74969",
      "title": "Use-after-free in the Layout: Text and Fonts component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00396,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74978",
      "url": "https://patchblox.com/security/cve/CVE-2026-74978",
      "title": "Clickjacking issue in the Widget component",
      "priority": "High",
      "cvss": 8.1,
      "epss": 0.00381,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74946",
      "url": "https://patchblox.com/security/cve/CVE-2026-74946",
      "title": "Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00334,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74983",
      "url": "https://patchblox.com/security/cve/CVE-2026-74983",
      "title": "Mitigation bypass in the Data Loss Prevention component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.1,
      "epss": 0.00328,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74971",
      "url": "https://patchblox.com/security/cve/CVE-2026-74971",
      "title": "Information disclosure in the DOM: UI Events \u0026 Focus Handling component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.00324,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74941",
      "url": "https://patchblox.com/security/cve/CVE-2026-74941",
      "title": "Privilege escalation in the Graphics: CanvasWebGL component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00323,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74976",
      "url": "https://patchblox.com/security/cve/CVE-2026-74976",
      "title": "JIT miscompilation in the JavaScript Engine: JIT component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.0032,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74949",
      "url": "https://patchblox.com/security/cve/CVE-2026-74949",
      "title": "Privilege escalation due to use-after-free in the Graphics: Canvas2D component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00318,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74948",
      "url": "https://patchblox.com/security/cve/CVE-2026-74948",
      "title": "Information disclosure in the Graphics component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.00314,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74935",
      "url": "https://patchblox.com/security/cve/CVE-2026-74935",
      "title": "Privilege escalation in the DOM: Networking component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.0031,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74939",
      "url": "https://patchblox.com/security/cve/CVE-2026-74939",
      "title": "Privilege escalation in the DOM: Navigation component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00304,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74942",
      "url": "https://patchblox.com/security/cve/CVE-2026-74942",
      "title": "Privilege escalation in the Remote Settings Client component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00304,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74965",
      "url": "https://patchblox.com/security/cve/CVE-2026-74965",
      "title": "Privilege escalation in the Shell Integration component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00303,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74957",
      "url": "https://patchblox.com/security/cve/CVE-2026-74957",
      "title": "Mitigation bypass in the Safe Browsing component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.1,
      "epss": 0.003,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74953",
      "url": "https://patchblox.com/security/cve/CVE-2026-74953",
      "title": "Privilege escalation in the Networking: Cookies component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00297,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74972",
      "url": "https://patchblox.com/security/cve/CVE-2026-74972",
      "title": "Information disclosure in the DOM: Push Subscriptions component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.00261,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-100832",
      "url": "https://patchblox.com/security/cve/CVE-2026-100832",
      "title": "Use-after-free in the Graphics: Canvas2D component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.8,
      "epss": 0.00245,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74981",
      "url": "https://patchblox.com/security/cve/CVE-2026-74981",
      "title": "Site isolation issue in the Audio/Video: Web Codecs component",
      "priority": "High",
      "cvss": 8.1,
      "epss": 0.00209,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74973",
      "url": "https://patchblox.com/security/cve/CVE-2026-74973",
      "title": "Race condition, use-after-free in the Graphics component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.00175,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74960",
      "url": "https://patchblox.com/security/cve/CVE-2026-74960",
      "title": "Site isolation issue in the WebExtensions component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.1,
      "epss": 0.00164,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74962",
      "url": "https://patchblox.com/security/cve/CVE-2026-74962",
      "title": "Site isolation issue in the Networking: Cookies component",
      "priority": "High",
      "severity": "high",
      "cvss": 8.1,
      "epss": 0.00164,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74934",
      "url": "https://patchblox.com/security/cve/CVE-2026-74934",
      "title": "Site isolation issue in the Graphics: CanvasWebGL component",
      "priority": "High",
      "severity": "high",
      "cvss": 7.5,
      "epss": 0.00158,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74974",
      "url": "https://patchblox.com/security/cve/CVE-2026-74974",
      "title": "Same-origin policy bypass in the Graphics: ImageLib component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.00135,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74963",
      "url": "https://patchblox.com/security/cve/CVE-2026-74963",
      "title": "Same-origin policy bypass in the Networking: Cookies component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.00124,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74967",
      "url": "https://patchblox.com/security/cve/CVE-2026-74967",
      "title": "Same-origin policy bypass in the Audio/Video: Playback component",
      "priority": "High",
      "severity": "medium",
      "cvss": 7.5,
      "epss": 0.00124,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74984",
      "url": "https://patchblox.com/security/cve/CVE-2026-74984",
      "title": "Race condition in the JavaScript Engine component",
      "priority": "Routine",
      "cvss": 6.8,
      "epss": 0.00278,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74968",
      "url": "https://patchblox.com/security/cve/CVE-2026-74968",
      "title": "Site isolation issue in the Graphics: WebRender component",
      "priority": "Routine",
      "severity": "important",
      "cvss": 5.4,
      "epss": 0.00158,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2026-74970",
      "url": "https://patchblox.com/security/cve/CVE-2026-74970",
      "title": "Site isolation issue in the Graphics component",
      "priority": "Routine",
      "cvss": 5.4,
      "epss": 0.00158,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    }
  ],
  "dataAsOf": "2026-11-09T19:38:12Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}