The version of Thunderbird installed on the remote macOS or Mac OS X host is prior to 156.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-94 advisory.

  - Privilege escalation in the Enterprise Policies component. This vulnerability was fixed in Firefox 156,     Firefox ESR 153.3, and Thunderbird 156. (CVE-2026-92073)

  - A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential     memory safety violations. (CVE-2026-92238)

  - A maliciously constructed IMAP line could cause an out-of-bounds buffer read. (CVE-2026-92239)

  - A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP response parser by     sending an untagged ' ID' response, crashing Thunderbird. The affected parsing path is reachable before     authentication. (CVE-2026-92240)

  - Use-after-free in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 156,     Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 140.16. (CVE-2026-92005)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Thunderbird installed on the remote Windows host is prior to 156.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-94 advisory.

  - Privilege escalation in the Enterprise Policies component. This vulnerability was fixed in Firefox 156,     Firefox ESR 153.3, and Thunderbird 156. (CVE-2026-92073)

  - A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential     memory safety violations. (CVE-2026-92238)

  - A maliciously constructed IMAP line could cause an out-of-bounds buffer read. (CVE-2026-92239)

  - A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP response parser by     sending an untagged ' ID' response, crashing Thunderbird. The affected parsing path is reachable before     authentication. (CVE-2026-92240)

  - Use-after-free in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 156,     Firefox ESR 140.16, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 140.16. (CVE-2026-92005)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Firefox installed on the remote Windows host is prior to 156.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-90 advisory.

  - Privilege escalation in the Memory component. This vulnerability was fixed in Firefox 156 and Firefox ESR     153.3. (CVE-2026-92054)

  - Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 156, Firefox     ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3. (CVE-2026-92015)

  - Use-after-free in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 156,     Firefox ESR 140.16, and Firefox ESR 153.3. (CVE-2026-92005)

  - Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This     vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.
    (CVE-2026-92006, CVE-2026-92007, CVE-2026-92008, CVE-2026-92009, CVE-2026-92010, CVE-2026-92011,     CVE-2026-92012, CVE-2026-92013)

  - Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was     fixed in Firefox 156 and Firefox ESR 153.3. (CVE-2026-92035)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Firefox installed on the remote macOS or Mac OS X host is prior to 156.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-90 advisory.

  - Privilege escalation in the Memory component. This vulnerability was fixed in Firefox 156 and Firefox ESR     153.3. (CVE-2026-92054)

  - Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 156, Firefox     ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3. (CVE-2026-92015)

  - Use-after-free in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 156,     Firefox ESR 140.16, and Firefox ESR 153.3. (CVE-2026-92005)

  - Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component. This     vulnerability was fixed in Firefox 156, Firefox ESR 115.41, Firefox ESR 140.16, and Firefox ESR 153.3.
    (CVE-2026-92006, CVE-2026-92007, CVE-2026-92008, CVE-2026-92009, CVE-2026-92010, CVE-2026-92011,     CVE-2026-92012, CVE-2026-92013)

  - Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was     fixed in Firefox 156 and Firefox ESR 153.3. (CVE-2026-92035)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 156 and     Thunderbird 156. (CVE-2026-92040)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Published	Updated	Severity
346176	Mozilla Thunderbird < 156.0	Nessus	MacOS X Local Security Checks	9/16/2026	9/16/2026	high
346179	Mozilla Thunderbird < 156.0	Nessus	Windows	9/16/2026	9/16/2026	high
345901	Mozilla Firefox < 156.0	Nessus	Windows	9/15/2026	9/16/2026	high
345903	Mozilla Firefox < 156.0	Nessus	MacOS X Local Security Checks	9/15/2026	9/16/2026	high
346400	Linux Distros Unpatched Vulnerability : CVE-2026-92040	Nessus	Misc.	9/16/2026	9/16/2026	critical

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