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.

The remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4775 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4775-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/               Emilio Pozuelo Monfort     September 07, 2026                            https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : thunderbird     Version        : 1:140.15.0esr-1~deb12u1     CVE ID         : CVE-2026-16365 CVE-2026-16371 CVE-2026-75874 CVE-2026-84119                      CVE-2026-84120 CVE-2026-84121 CVE-2026-84122 CVE-2026-84124                      CVE-2026-84131 CVE-2026-84143 CVE-2026-84145 CVE-2026-84639                      CVE-2026-84640 CVE-2026-84641

    Multiple security issues were discovered in Thunderbird, which could     result in the execution of arbitrary code or information disclosure.

    For Debian 12 bookworm, these problems have been fixed in version     1:140.15.0esr-1~deb12u1.

    We recommend that you upgrade your thunderbird packages.

    For the detailed security status of thunderbird please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/thunderbird

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian 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 mozilla-firefox installed on the remote host is prior to 140.15.0esr / 153.2.0esr. It is, therefore, affected by multiple vulnerabilities as referenced in the SSA:2026-247-02 advisory.

    New mozilla-firefox packages are available for Slackware 15.0 and -current to fix security issues.

Tenable has extracted the preceding description block directly from the mozilla-firefox 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 mozilla-thunderbird installed on the remote host is prior to 140.15.0esr / 153.2.0esr. It is, therefore, affected by multiple vulnerabilities as referenced in the SSA:2026-247-03 advisory.

    New mozilla-thunderbird packages are available for Slackware 15.0 and -current to fix security issues.

Tenable has extracted the preceding description block directly from the mozilla-thunderbird 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 remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6483 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6483-1                   security@debian.org     https://www.debian.org/security/                       Moritz Muehlenhoff     September 04, 2026                    https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : thunderbird     CVE ID         : CVE-2026-16365 CVE-2026-16371 CVE-2026-75874 CVE-2026-84119                      CVE-2026-84120 CVE-2026-84121 CVE-2026-84122 CVE-2026-84124                      CVE-2026-84131 CVE-2026-84143 CVE-2026-84145 CVE-2026-84639                      CVE-2026-84640 CVE-2026-84641

    Multiple security issues were discovered in Thunderbird, which could     result in the execution of arbitrary code or information disclosure.

    For the stable distribution (trixie), these problems have been fixed in     version 1:140.15.0esr-1~deb13u1.

    We recommend that you upgrade your thunderbird packages.

    For the detailed security status of thunderbird please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/thunderbird

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian 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 remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4770 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4770-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/               Emilio Pozuelo Monfort     September 04, 2026                            https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : firefox-esr     Version        : 140.15.0esr-1~deb12u1     CVE ID         : CVE-2026-16365 CVE-2026-16371 CVE-2026-75874 CVE-2026-84119                      CVE-2026-84120 CVE-2026-84121 CVE-2026-84122 CVE-2026-84124                      CVE-2026-84131 CVE-2026-84143 CVE-2026-84145

    Multiple security issues have been found in the Mozilla Firefox web     browser, which could potentially result in the execution of arbitrary     code, sandbox escape or privilege escalation.

    For Debian 12 bookworm, these problems have been fixed in version     140.15.0esr-1~deb12u1.

    We recommend that you upgrade your firefox-esr packages.

    For the detailed security status of firefox-esr please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/firefox-esr

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian 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 remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6481 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6481-1                   security@debian.org     https://www.debian.org/security/                       Moritz Muehlenhoff     September 02, 2026                    https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : firefox-esr     CVE ID         : CVE-2026-16365 CVE-2026-16371 CVE-2026-75874 CVE-2026-84119                      CVE-2026-84120 CVE-2026-84121 CVE-2026-84122 CVE-2026-84124                      CVE-2026-84131 CVE-2026-84143 CVE-2026-84145

    Multiple security issues have been found in the Mozilla Firefox web     browser, which could potentially result in the execution of arbitrary     code, sandbox escape or privilege escalation.

    For the stable distribution (trixie), these problems have been fixed in     version 140.15.0esr-1~deb13u1.

    We recommend that you upgrade your firefox-esr packages.

    For the detailed security status of firefox-esr please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/firefox-esr

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian 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 macOS or Mac OS X host is prior to 153.2. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-88 advisory.

  - Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird     140.15, and Thunderbird 153.2. (CVE-2026-84131)

  - 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)

  - Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used.
    (CVE-2026-84639)

  - A maliciously constructed mail header could lead to a one byte read past the end of a buffer.
    (CVE-2026-84640)

  - A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID     response. Heap contents can ultimately be persisted to prefs.js. (CVE-2026-84641)

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 153.2. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-88 advisory.

  - Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird     140.15, and Thunderbird 153.2. (CVE-2026-84131)

  - 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)

  - Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used.
    (CVE-2026-84639)

  - A maliciously constructed mail header could lead to a one byte read past the end of a buffer.
    (CVE-2026-84640)

  - A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID     response. Heap contents can ultimately be persisted to prefs.js. (CVE-2026-84641)

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 140.15. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-87 advisory.

  - Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird     140.15, and Thunderbird 153.2. (CVE-2026-84131)

  - 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)

  - Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used.
    (CVE-2026-84639)

  - A maliciously constructed mail header could lead to a one byte read past the end of a buffer.
    (CVE-2026-84640)

  - A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID     response. Heap contents can ultimately be persisted to prefs.js. (CVE-2026-84641)

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 140.15. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-87 advisory.

  - Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird     140.15, and Thunderbird 153.2. (CVE-2026-84131)

  - 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)

  - Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used.
    (CVE-2026-84639)

  - A maliciously constructed mail header could lead to a one byte read past the end of a buffer.
    (CVE-2026-84640)

  - A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID     response. Heap contents can ultimately be persisted to prefs.js. (CVE-2026-84641)

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 ESR installed on the remote macOS or Mac OS X host is prior to 153.2. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-85 advisory.

  - Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84131)

  - 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, and Firefox ESR 153.2. (CVE-2026-75874)

  - Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 155 and Firefox     ESR 153.2. (CVE-2026-84118)

  - Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84119)

  - Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR     115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84120)

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 ESR installed on the remote Windows host is prior to 153.2. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-85 advisory.

  - Privilege escalation due to invalid pointer in the Graphics component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84131)

  - 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, and Firefox ESR 153.2. (CVE-2026-75874)

  - Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 155 and Firefox     ESR 153.2. (CVE-2026-84118)

  - Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84119)

  - Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR     115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84120)

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 ESR installed on the remote Windows host is prior to 115.40. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-83 advisory.

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

  - Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84119)

  - Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR     115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84120)

  - Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84121)

  - Internally found bugs present in Firefox 154, Firefox ESR 153.1, Firefox ESR 140.14 and Firefox ESR     115.39. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we     presume that with enough effort some of these could have been exploited. (CVE-2026-84145)

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 ESR installed on the remote macOS or Mac OS X host is prior to 115.40. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-83 advisory.

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

  - Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84119)

  - Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR     115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84120)

  - Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in     Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84121)

  - Internally found bugs present in Firefox 154, Firefox ESR 153.1, Firefox ESR 140.14 and Firefox ESR     115.39. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we     presume that with enough effort some of these could have been exploited. (CVE-2026-84145)

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 ESR installed on the remote macOS or Mac OS X host is prior to 140.15. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-84 advisory.

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

  - Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 153,     Thunderbird 153, and Firefox ESR 140.15. (CVE-2026-16365)

  - Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR     115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84120)

  - Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR     140.15, and Firefox ESR 153.2. (CVE-2026-84122)

  - Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153,     Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13, and Firefox ESR 140.15. (CVE-2026-16371)

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 ESR installed on the remote Windows host is prior to 140.15. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-84 advisory.

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

  - Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 153,     Thunderbird 153, and Firefox ESR 140.15. (CVE-2026-16365)

  - Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR     115.40, Firefox ESR 140.15, and Firefox ESR 153.2. (CVE-2026-84120)

  - Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR     140.15, and Firefox ESR 153.2. (CVE-2026-84122)

  - Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153,     Firefox ESR 140.13, Thunderbird 153, Thunderbird 140.13, and Firefox ESR 140.15. (CVE-2026-16371)

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 remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:3658-1 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 remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-fc11919789 advisory.

    Implement buffer stride support for PipeWire camera.

    ----

    - 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.

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.

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

  - 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)

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

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 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 version of Firefox installed on the remote Windows host is prior to 154.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-74 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)

  - Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154 and     Thunderbird 154. (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)

  - 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)

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 154.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-74 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)

  - Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154 and     Thunderbird 154. (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)

  - 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)

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	Type	Severity
343416	Debian dla-4775 : thunderbird - security update	Nessus	Debian Local Security Checks	Local	critical
343052	Slackware Linux 15.0 / current mozilla-firefox Multiple Vulnerabilities (SSA:2026-247-02)	Nessus	Slackware Local Security Checks	Local	critical
343051	Slackware Linux 15.0 / current mozilla-thunderbird Multiple Vulnerabilities (SSA:2026-247-03)	Nessus	Slackware Local Security Checks	Local	critical
342858	Debian dsa-6483 : thunderbird - security update	Nessus	Debian Local Security Checks	Local	critical
342790	Debian dla-4770 : firefox-esr - security update	Nessus	Debian Local Security Checks	Local	critical
342446	Debian dsa-6481 : firefox-esr - security update	Nessus	Debian Local Security Checks	Local	critical
342260	Mozilla Thunderbird < 153.2	Nessus	MacOS X Local Security Checks	Local	critical
342259	Mozilla Thunderbird < 153.2	Nessus	Windows	Local	critical
342258	Mozilla Thunderbird < 140.15	Nessus	Windows	Local	critical
342257	Mozilla Thunderbird < 140.15	Nessus	MacOS X Local Security Checks	Local	critical
342203	Mozilla Firefox ESR < 153.2	Nessus	MacOS X Local Security Checks	Local	critical
342202	Mozilla Firefox ESR < 153.2	Nessus	Windows	Local	critical
342166	Mozilla Firefox ESR < 115.40	Nessus	Windows	Local	critical
342165	Mozilla Firefox ESR < 115.40	Nessus	MacOS X Local Security Checks	Local	critical
342132	Mozilla Firefox ESR < 140.15	Nessus	MacOS X Local Security Checks	Local	critical
342131	Mozilla Firefox ESR < 140.15	Nessus	Windows	Local	critical
339734	SUSE SLES12: MozillaFirefox / MozillaFirefox-devel / etc (SUSE-SU-2026:3683-1)	Nessus	SuSE Local Security Checks	Local	critical
338826	SUSE SLED15: MozillaFirefox / MozillaFirefox-devel / etc (SUSE-SU-2026:3658-1)	Nessus	SuSE Local Security Checks	Local	critical
338389	Fedora 44 : firefox (2026-fc11919789)	Nessus	Fedora Local Security Checks	Local	critical
338384	Fedora 43 : firefox (2026-170e9d62c6)	Nessus	Fedora Local Security Checks	Local	critical
338086	Linux Distros Unpatched Vulnerability : CVE-2026-75874	Nessus	Misc.	Local	critical
337889	Mozilla Thunderbird < 154.0	Nessus	MacOS X Local Security Checks	Local	critical
337888	Mozilla Thunderbird < 154.0	Nessus	Windows	Local	critical
337629	Mozilla Firefox < 154.0	Nessus	Windows	Local	critical
337625	Mozilla Firefox < 154.0	Nessus	MacOS X Local Security Checks	Local	critical

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CVE-2026-75874

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