The version of Firefox ESR installed on the remote Windows host is prior to 153.1. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-77 advisory.

  - Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74944)

  - Site isolation issue in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74934)

  - Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74935)

  - Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154,     Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
    (CVE-2026-74936)

  - Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR     153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74937)

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 154.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-78 advisory.

  - Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74944)

  - Malicious calendar invitations could use file URI attachments to launch local or network-hosted     executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new     invitation display enabled, the attachment could also appear under a misleading filename. (CVE-2026-84637)

  - Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154,     Thunderbird 154, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 140.15, and     Thunderbird 153.2. (CVE-2026-75874)

  - Site isolation issue in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74934)

  - Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74935)

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

The remote SUSE Linux SLES12 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:3683-1 advisory.

    Update to Firefox Extended Support Release 140.14.0 ESR.

    - MFSA 2026-74 (bsc#1274867):
      - CVE-2026-74934: Site isolation issue in the Graphics: CanvasWebGL component.
      - CVE-2026-74935: Privilege escalation in the DOM: Networking component.
      - CVE-2026-74936: Use-after-free in the JavaScript: WebAssembly component.
      - CVE-2026-74937: Use-after-free in the JavaScript: GC component.
      - CVE-2026-74938: Mitigation bypass in the JavaScript: GC component.
      - CVE-2026-74939: Privilege escalation in the DOM: Navigation component.
      - CVE-2026-74940: Use-after-free in the Graphics: Text component.
      - CVE-2026-74941: Privilege escalation in the Graphics: CanvasWebGL component.
      - CVE-2026-74942: Privilege escalation in the Remote Settings Client component.
      - CVE-2026-74943: Use-after-free in the Graphics: ImageLib component.
      - CVE-2026-74944: Use-after-free in the DOM: Core & HTML component.
      - CVE-2026-74945: Information disclosure in the Graphics: Text component.
      - CVE-2026-74946: Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL     component.
      - CVE-2026-74947: Privilege escalation due to invalid pointer in the Graphics component.
      - CVE-2026-74948: Information disclosure in the Graphics component.
      - CVE-2026-74949: Privilege escalation due to use-after-free in the Graphics: Canvas2D component.
      - CVE-2026-74950: Privilege escalation in the Downloads API component.
      - CVE-2026-74951: Clickjacking issue in Firefox for Android.
      - CVE-2026-74952: Privilege escalation in the Application Update component.
      - CVE-2026-74953: Privilege escalation in the Networking: Cookies component.
      - CVE-2026-74954: Information disclosure due to side-channel in the Storage: Cache API component.
      - CVE-2026-74955: Privilege escalation in the Request Handling component.
      - CVE-2026-74956: Same-origin policy bypass in the DOM: Service Workers component.
      - CVE-2026-74957: Mitigation bypass in the Safe Browsing component.
      - CVE-2026-74958: Information disclosure in the WebRTC component.
      - CVE-2026-74959: Mitigation bypass in the Storage: Cache API component.
      - CVE-2026-74960: Site isolation issue in the WebExtensions component.
      - CVE-2026-74961: Side-channel in the Web Audio component.
      - CVE-2026-74962: Site isolation issue in the Networking: Cookies component.
      - CVE-2026-74963: Same-origin policy bypass in the Networking: Cookies component.
      - CVE-2026-74964: Integer overflow in the Graphics component.
      - CVE-2026-74965: Privilege escalation in the Shell Integration component.
      - CVE-2026-74966: Information disclosure in the Form Autofill component.
      - CVE-2026-74967: Same-origin policy bypass in the Audio/Video: Playback component.
      - CVE-2026-74968: Site isolation issue in the Graphics: WebRender component.
      - CVE-2026-74969: Use-after-free in the Layout: Text and Fonts component.
      - CVE-2026-74970: Site isolation issue in the Graphics component.
      - CVE-2026-74971: Information disclosure in the DOM: UI Events & Focus Handling component.
      - CVE-2026-74972: Information disclosure in the DOM: Push Subscriptions component.
      - CVE-2026-74973: Race condition, use-after-free in the Graphics component.
      - CVE-2026-74974: Same-origin policy bypass in the Graphics: ImageLib component.
      - CVE-2026-74975: Spoofing issue in the Downloads component in Firefox for Android.
      - CVE-2026-74976: JIT miscompilation in the JavaScript Engine: JIT component.
      - CVE-2026-74977: Integer overflow in the Graphics component.
      - CVE-2026-74978: Clickjacking issue in the Widget component.
      - CVE-2026-74979: Mitigation bypass in the Add-ons Manager component.
      - CVE-2026-74980: Clickjacking issue in the Downloads component in Firefox for Android.
      - CVE-2026-74981: Site isolation issue in the Audio/Video: Web Codecs component.
      - CVE-2026-74982: Denial-of-service in the Widget component.
      - CVE-2026-74983: Mitigation bypass in the Data Loss Prevention component.
      - CVE-2026-74984: Race condition in the JavaScript Engine component.
      - CVE-2026-74985: Privilege escalation in the Enterprise Policies component.
      - CVE-2026-74986: Site isolation issue in the CSS Parsing and Computation component.
      - CVE-2026-74987: Internally found bugs fixed in Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154.
      - CVE-2026-74988: Internally found bugs fixed in Firefox ESR 153.1 and Firefox 154.
      - CVE-2026-74989: Internally found bugs fixed in Firefox 154.
      - CVE-2026-74990: Internally found bugs fixed in Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR     153.1 and         Firefox 154.
      - CVE-2026-75874: Sandbox escape in the Remote Settings Client component.

Tenable has extracted the preceding description block directly from the SUSE 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 Thunderbird installed on the remote Windows host is prior to 154.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-78 advisory.

  - Use-after-free in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 154, Firefox ESR     140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74944)

  - Malicious calendar invitations could use file URI attachments to launch local or network-hosted     executables on Windows, bypassing Thunderbird's normal executable attachment protections. With the new     invitation display enabled, the attachment could also appear under a misleading filename. (CVE-2026-84637)

  - Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154,     Thunderbird 154, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 140.15, and     Thunderbird 153.2. (CVE-2026-75874)

  - Site isolation issue in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74934)

  - Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154,     Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and     Thunderbird 153.1. (CVE-2026-74935)

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 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-170e9d62c6 advisory.

    - Update to latest upstream (154.0)
    - Enabled Wayland session restore on KDE.

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.

ID	名前	製品	ファミリー	公開日	更新日	深刻度
337628	Mozilla Firefox ESR < 153.1	Nessus	Windows	2026/8/18	2026/8/24	critical
337889	Mozilla Thunderbird < 154.0	Nessus	MacOS X Local Security Checks	2026/8/19	2026/9/4	critical
339734	SUSE SLES12: MozillaFirefox / MozillaFirefox-devel / etc (SUSE-SU-2026:3683-1)	Nessus	SuSE Local Security Checks	2026/8/26	2026/8/28	critical
342669	openSUSE 16: MozillaFirefox / MozillaFirefox-branding-upstream / etc (openSUSE-SU-2026:21713-1)	Nessus	SuSE Local Security Checks	2026/9/3	2026/9/3	critical
337888	Mozilla Thunderbird < 154.0	Nessus	Windows	2026/8/19	2026/9/4	critical
338384	Fedora 43 : firefox (2026-170e9d62c6)	Nessus	Fedora Local Security Checks	2026/8/20	2026/10/29	critical

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