{
  "fix": "Mozilla Thunderbird (en-US) 78.10.0",
  "url": "https://patchblox.com/security/fix/windows-app/mozilla.thunderbird-78.10.0",
  "summary": "Mozilla Thunderbird (en-US) 78.10.0, released April 15, 2021, fixes 46 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) 78.10.0",
  "released": "2021-04-15T00:00:00Z",
  "priority": "Urgent",
  "priorityTier": 2,
  "priorityReason": "Closes CVE-2021-23978, rated Critical",
  "supported": true,
  "cveCount": 46,
  "exploitedCveCount": 0,
  "kevCveCount": 0,
  "ransomwareCveCount": 0,
  "maxEpss": 0.42327,
  "maxCvss": 9.8,
  "appliesTo": [
    {
      "product": "Mozilla Thunderbird (en-US)",
      "productUrl": "https://patchblox.com/security/product/windows-app/mozilla-thunderbird-en-us",
      "fixedVersion": "78.10.0",
      "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-2021-23978",
      "url": "https://patchblox.com/security/cve/CVE-2021-23978",
      "title": "Firefox ESR and 2 others: Mozilla developers reported memory safety bugs present in Firefox 85 and Firefox ESR 78.7.",
      "priority": "Urgent",
      "severity": "Critical",
      "cvss": 8.8,
      "epss": 0.0153,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23968",
      "url": "https://patchblox.com/security/cve/CVE-2021-23968",
      "title": "Firefox ESR and 2 others: If Content Security Policy blocked frame navigation, the full destination of a redirect served in the\u2026",
      "priority": "Urgent",
      "severity": "Critical",
      "cvss": 4.3,
      "epss": 0.01307,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23969",
      "url": "https://patchblox.com/security/cve/CVE-2021-23969",
      "title": "Firefox ESR and 2 others: As specified in the W3C Content Security Policy draft, when creating a violation report, \u0022User agents\u2026",
      "priority": "Urgent",
      "severity": "Critical",
      "cvss": 4.3,
      "epss": 0.01212,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26950",
      "url": "https://patchblox.com/security/cve/CVE-2020-26950",
      "title": "Firefox ESR and 2 others: In certain circumstances, the MCallGetProperty opcode can be emitted with unmet assumptions resulting\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.42327,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26971",
      "url": "https://patchblox.com/security/cve/CVE-2020-26971",
      "title": "Firefox ESR and 2 others: Certain blit values provided by the user were not properly constrained leading to a heap buffer overflow\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01899,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23994",
      "url": "https://patchblox.com/security/cve/CVE-2021-23994",
      "title": "Firefox ESR and 2 others: A WebGL framebuffer was not initialized early enough, resulting in memory corruption and an out of bound\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01756,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26973",
      "url": "https://patchblox.com/security/cve/CVE-2020-26973",
      "title": "Firefox ESR and 2 others: Certain input to the CSS Sanitizer confused it, resulting in incorrect components being removed.",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01623,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-35113",
      "url": "https://patchblox.com/security/cve/CVE-2020-35113",
      "title": "Firefox ESR and 2 others: Mozilla developers reported memory safety bugs present in Firefox 83 and Firefox ESR 78.5.",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01572,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26960",
      "url": "https://patchblox.com/security/cve/CVE-2020-26960",
      "title": "Firefox ESR and 2 others: If the Compact() method was called on an nsTArray, the array could have been reallocated without updating\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01563,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26974",
      "url": "https://patchblox.com/security/cve/CVE-2020-26974",
      "title": "Firefox ESR and 2 others: When flex-basis was used on a table wrapper, a StyleGenericFlexBasis object could have been incorrectly\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01533,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26968",
      "url": "https://patchblox.com/security/cve/CVE-2020-26968",
      "title": "Firefox ESR and 2 others: Mozilla developers reported memory safety bugs present in Firefox 82 and Firefox ESR 78.4.",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01514,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23987",
      "url": "https://patchblox.com/security/cve/CVE-2021-23987",
      "title": "Firefox ESR and 2 others: Mozilla developers and community members reported memory safety bugs present in Firefox 86 and Firefox\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01416,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23999",
      "url": "https://patchblox.com/security/cve/CVE-2021-23999",
      "title": "Firefox ESR and 2 others: If a Blob URL was loaded through some unusual user interaction, it could have been loaded by the System\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01372,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23964",
      "url": "https://patchblox.com/security/cve/CVE-2021-23964",
      "title": "Firefox ESR and 2 others: Mozilla developers reported memory safety bugs present in Firefox 84 and Firefox ESR 78.6.",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01361,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-29946",
      "url": "https://patchblox.com/security/cve/CVE-2021-29946",
      "title": "Firefox ESR and 2 others: Ports that were written as an integer overflow above the bounds of a 16-bit integer could have bypassed\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01303,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26959",
      "url": "https://patchblox.com/security/cve/CVE-2020-26959",
      "title": "Firefox ESR and 2 others: During browser shutdown, reference decrementing could have occured on a previously freed object, resulting\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01297,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23960",
      "url": "https://patchblox.com/security/cve/CVE-2021-23960",
      "title": "Firefox ESR and 2 others: Performing garbage collection on re-declared JavaScript variables resulted in a user-after-poison, and\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01289,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-35112",
      "url": "https://patchblox.com/security/cve/CVE-2020-35112",
      "title": "Firefox ESR and 2 others: If a user downloaded a file lacking an extension on Windows, and then \u0022Open\u0022-ed it from the downloads\u2026",
      "priority": "High",
      "cvss": 8.8,
      "epss": 0.01274,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26970",
      "url": "https://patchblox.com/security/cve/CVE-2020-26970",
      "title": "Thunderbird: When reading SMTP server status codes, Thunderbird writes an integer value to a position on the stack\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01247,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23954",
      "url": "https://patchblox.com/security/cve/CVE-2021-23954",
      "title": "Firefox ESR and 2 others: Using the new logical assignment operators in a JavaScript switch statement could have caused a type\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01186,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23995",
      "url": "https://patchblox.com/security/cve/CVE-2021-23995",
      "title": "Firefox ESR and 2 others: When Responsive Design Mode was enabled, it used references to objects that were previously freed.",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01181,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23981",
      "url": "https://patchblox.com/security/cve/CVE-2021-23981",
      "title": "Firefox ESR and 2 others: A texture upload of a Pixel Buffer Object could have confused the WebGL code to skip binding the buffer\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.1,
      "epss": 0.01145,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-24002",
      "url": "https://patchblox.com/security/cve/CVE-2021-24002",
      "title": "Firefox ESR and 2 others: When a user clicked on an FTP URL containing encoded newline characters (%0A and %0D), the newlines would\u2026",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.01125,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-4127",
      "url": "https://patchblox.com/security/cve/CVE-2021-4127",
      "title": "Thunderbird: An out of date graphics library (Angle) likely contained vulnerabilities that could potentially be exploited.",
      "priority": "High",
      "severity": "Important",
      "cvss": 9.8,
      "epss": 0.00945,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-15685",
      "url": "https://patchblox.com/security/cve/CVE-2020-15685",
      "title": "Thunderbird: Improper Neutralization of Special Elements used in a Command (\u0027Command Injection\u0027)",
      "priority": "High",
      "severity": "Important",
      "cvss": 8.8,
      "epss": 0.00881,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-29950",
      "url": "https://patchblox.com/security/cve/CVE-2021-29950",
      "title": "Thunderbird: Thunderbird unprotects a secret OpenPGP key prior to using it for a decryption, signing or key import\u2026",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 7.5,
      "epss": 0.00853,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-29949",
      "url": "https://patchblox.com/security/cve/CVE-2021-29949",
      "title": "Thunderbird: When loading the shared library that provides the OTR protocol implementation, Thunderbird will initially\u2026",
      "priority": "High",
      "severity": "Moderate",
      "cvss": 7.8,
      "epss": 0.00316,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-35111",
      "url": "https://patchblox.com/security/cve/CVE-2020-35111",
      "title": "Firefox ESR and 2 others: When an extension with the proxy permission registered to receive \u003Call_urls\u003E, the proxy.onRequest callback\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 4.3,
      "epss": 0.01432,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23973",
      "url": "https://patchblox.com/security/cve/CVE-2021-23973",
      "title": "Firefox ESR and 2 others: When trying to load a cross-origin resource in an audio/video context a decoding error may have resulted,\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.01368,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26958",
      "url": "https://patchblox.com/security/cve/CVE-2020-26958",
      "title": "Firefox ESR and 2 others: Firefox did not block execution of scripts with incorrect MIME types when the response was intercepted\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.1,
      "epss": 0.01364,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26966",
      "url": "https://patchblox.com/security/cve/CVE-2020-26966",
      "title": "Firefox ESR and 2 others: Searching for a single word from the address bar caused an mDNS request to be sent on the local network\u2026",
      "priority": "Routine",
      "cvss": 6.5,
      "epss": 0.01354,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26978",
      "url": "https://patchblox.com/security/cve/CVE-2020-26978",
      "title": "Firefox ESR and 2 others: Using techniques that built on the slipstream research, a malicious webpage could have exposed both an\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.1,
      "epss": 0.01334,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26953",
      "url": "https://patchblox.com/security/cve/CVE-2020-26953",
      "title": "Firefox ESR and 2 others: It was possible to cause the browser to enter fullscreen mode without displaying the security UI; thus\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 4.3,
      "epss": 0.01293,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26965",
      "url": "https://patchblox.com/security/cve/CVE-2020-26965",
      "title": "Firefox ESR and 2 others: Some websites have a feature \u0022Show Password\u0022 where clicking a button will change a password field into\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.01262,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26956",
      "url": "https://patchblox.com/security/cve/CVE-2020-26956",
      "title": "Firefox ESR and 2 others: In some cases, removing HTML elements during sanitization would keep existing SVG event handlers and\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.1,
      "epss": 0.01233,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-29945",
      "url": "https://patchblox.com/security/cve/CVE-2021-29945",
      "title": "Firefox ESR and 2 others: The WebAssembly JIT could miscalculate the size of a return type, which could lead to a null read and\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.01202,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26961",
      "url": "https://patchblox.com/security/cve/CVE-2020-26961",
      "title": "Firefox ESR and 2 others: When DNS over HTTPS is in use, it intentionally filters RFC1918 and related IP ranges from the responses\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.01165,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23984",
      "url": "https://patchblox.com/security/cve/CVE-2021-23984",
      "title": "Firefox ESR and 2 others: A malicious extension could have opened a popup window lacking an address bar.",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.01113,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23953",
      "url": "https://patchblox.com/security/cve/CVE-2021-23953",
      "title": "Firefox ESR and 2 others: If a user clicked into a specifically crafted PDF, the PDF reader could be confused into leaking cross-origin\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 4.3,
      "epss": 0.01056,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2020-26951",
      "url": "https://patchblox.com/security/cve/CVE-2020-26951",
      "title": "Firefox ESR and 2 others: A parsing and event loading mismatch in Firefox\u0027s SVG code could have allowed load events to fire, even\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.1,
      "epss": 0.01051,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23991",
      "url": "https://patchblox.com/security/cve/CVE-2021-23991",
      "title": "Thunderbird: If a Thunderbird user has previously imported Alice\u0027s OpenPGP key, and Alice has extended the validity\u2026",
      "priority": "Routine",
      "severity": "Moderate",
      "cvss": 6.8,
      "epss": 0.01035,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23982",
      "url": "https://patchblox.com/security/cve/CVE-2021-23982",
      "title": "Firefox ESR and 2 others: Using techniques that built on the slipstream research, a malicious webpage could have scanned both an\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.00743,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23998",
      "url": "https://patchblox.com/security/cve/CVE-2021-23998",
      "title": "Firefox ESR and 2 others: Through complicated navigations with new windows, an HTTP page could have inherited a secure lock icon\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 6.5,
      "epss": 0.00594,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23992",
      "url": "https://patchblox.com/security/cve/CVE-2021-23992",
      "title": "Thunderbird: Thunderbird did not check if the user ID associated with an OpenPGP key has a valid self signature.",
      "priority": "Routine",
      "severity": "Moderate",
      "cvss": 4.3,
      "epss": 0.00478,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-23993",
      "url": "https://patchblox.com/security/cve/CVE-2021-23993",
      "title": "Thunderbird: An attacker may perform a DoS attack to prevent a user from sending encrypted email to a correspondent.",
      "priority": "Routine",
      "severity": "Moderate",
      "cvss": 6.5,
      "epss": 0.00423,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    },
    {
      "cveId": "CVE-2021-29948",
      "url": "https://patchblox.com/security/cve/CVE-2021-29948",
      "title": "Thunderbird: Signatures are written to disk before and read during verification, which might be subject to a race\u2026",
      "priority": "Routine",
      "severity": "Important",
      "cvss": 2.5,
      "epss": 0.00286,
      "kev": false,
      "ransomware": false,
      "exploited": false,
      "disclosed": false
    }
  ],
  "dataAsOf": "2026-11-10T13:56:55Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}