The version of Thunderbird installed on the remote Windows host is prior to 150.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-33 advisory.

  - Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR     140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6771)

  - Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 150, Firefox ESR     115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6746)

  - Use-after-free in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10,     Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6747)

  - Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox     150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6748, CVE-2026-6751)

  - Information disclosure due to uninitialized memory in the Graphics: Canvas2D component. This vulnerability     was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
    (CVE-2026-6749)

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

The remote Fedora 44 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-fb08ad61f2 advisory.

    Update NSS to 3.122.1     Update to Firefox 150.0


    ----

    - New upstream release (149.0.2)

Tenable has extracted the preceding description block directly from the Fedora security advisory.

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 150.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-30 advisory.

  - Memory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149.
    Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of     these could have been exploited to run arbitrary code. (CVE-2026-6786)

  - Memory safety bugs present in Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of     memory corruption and we presume that with enough effort some of these could have been exploited to run     arbitrary code. (CVE-2026-6784)

  - Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149     and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with     enough effort some of these could have been exploited to run arbitrary code. (CVE-2026-6785)

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 150.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-30 advisory.

  - Memory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149.
    Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of     these could have been exploited to run arbitrary code. (CVE-2026-6786)

  - Memory safety bugs present in Firefox 149 and Thunderbird 149. Some of these bugs showed evidence of     memory corruption and we presume that with enough effort some of these could have been exploited to run     arbitrary code. (CVE-2026-6784)

  - Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149     and Thunderbird 149. Some of these bugs showed evidence of memory corruption and we presume that with     enough effort some of these could have been exploited to run arbitrary code. (CVE-2026-6785)

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 macOS or Mac OS X host is prior to 150.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-33 advisory.

  - Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR     140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6771)

  - Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 150, Firefox ESR     115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6746)

  - Use-after-free in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10,     Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6747)

  - Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox     150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6748, CVE-2026-6751)

  - Information disclosure due to uninitialized memory in the Graphics: Canvas2D component. This vulnerability     was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
    (CVE-2026-6749)

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

ID	Name	Product	Family	Published	Updated	Severity
309100	Mozilla Thunderbird < 150.0	Nessus	Windows	4/21/2026	4/27/2026	medium
310077	Fedora 44 : firefox / nss (2026-fb08ad61f2)	Nessus	Fedora Local Security Checks	4/24/2026	4/24/2026	medium
307899	Mozilla Firefox < 150.0	Nessus	Windows	4/21/2026	4/27/2026	medium
307895	Mozilla Firefox < 150.0	Nessus	MacOS X Local Security Checks	4/21/2026	4/27/2026	medium
309098	Mozilla Thunderbird < 150.0	Nessus	MacOS X Local Security Checks	4/21/2026	4/27/2026	medium

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