Spoofing issue in the Web Speech component. This vulnerability was fixed in Firefox 151 and Thunderbird 151.

The AlmaLinux 9.2 host has a package installed that is affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.2:CLSA-2026:1781204847 advisory.

  - Invalid pointer in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150,     Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6757)

  - Privilege escalation in the Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR     140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6761)

  - Incorrect boundary conditions in the DOM: Device Interfaces component. This vulnerability was fixed in     Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10. (CVE-2026-6764)

  - 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)

  - Spoofing issue in the Web Speech component. This vulnerability was fixed in Firefox 151 and Thunderbird     151. (CVE-2026-8963)

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 42 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-7f6ee801e2 advisory.

    Update NSS to 3.123.1     Update to Firefox 151.0


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.

  - Spoofing issue in the Web Speech component. This vulnerability was fixed in Firefox 151 and Thunderbird     151. (CVE-2026-8963)

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

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-f3409cf313 advisory.

    Updated to latest upstream (151.0)

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 packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-cd20332935 advisory.

    Update NSS to 3.123.1     Update to Firefox 151.0

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 Thunderbird installed on the remote macOS or Mac OS X host is prior to 151.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-50 advisory.

  - Memory safety bugs present in Thunderbird 140.10 and Thunderbird 150. 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-2026-8974, CVE-2026-8975)

  - Integer overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox     ESR 140.11, Thunderbird 151, and Thunderbird 140.11. (CVE-2026-8956)

  - Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in     Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
    (CVE-2026-8946)

  - Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151,     Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11. (CVE-2026-8947)

  - Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151     and Thunderbird 151. (CVE-2026-8948)

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 151.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-50 advisory.

  - Memory safety bugs present in Thunderbird 140.10 and Thunderbird 150. 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-2026-8974, CVE-2026-8975)

  - Integer overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox     ESR 140.11, Thunderbird 151, and Thunderbird 140.11. (CVE-2026-8956)

  - Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in     Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
    (CVE-2026-8946)

  - Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151,     Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11. (CVE-2026-8947)

  - Same-origin policy bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 151     and Thunderbird 151. (CVE-2026-8948)

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 151.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-46 advisory.

  - Memory safety bugs present in Firefox ESR 115.35, Firefox ESR 140.10 and Firefox 150. 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-2026-8975)

  - Integer overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox     ESR 140.11, Thunderbird 151, and Thunderbird 140.11. (CVE-2026-8956)

  - Sandbox escape in Firefox and Firefox Focus for Android. This vulnerability was fixed in Firefox 151.
    (CVE-2026-8945)

  - Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in     Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
    (CVE-2026-8946)

  - Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151,     Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11. (CVE-2026-8947)

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 151.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-46 advisory.

  - Memory safety bugs present in Firefox ESR 115.35, Firefox ESR 140.10 and Firefox 150. 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-2026-8975)

  - Integer overflow in the Networking: JAR component. This vulnerability was fixed in Firefox 151, Firefox     ESR 140.11, Thunderbird 151, and Thunderbird 140.11. (CVE-2026-8956)

  - Sandbox escape in Firefox and Firefox Focus for Android. This vulnerability was fixed in Firefox 151.
    (CVE-2026-8945)

  - Incorrect boundary conditions in the Audio/Video: Web Codecs component. This vulnerability was fixed in     Firefox 151, Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11.
    (CVE-2026-8946)

  - Use-after-free in the DOM: Bindings (WebIDL) component. This vulnerability was fixed in Firefox 151,     Firefox ESR 115.36, Firefox ESR 140.11, Thunderbird 151, and Thunderbird 140.11. (CVE-2026-8947)

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
360052	AlmaLinux 9.2 [TuxCare] Security Update: thunderbird Multiple Vulnerabilities (ALMALINUX9.2:CLSA-2026:1781204847)	Nessus	Alma Linux Local Security Checks	Local	critical
316628	Fedora 42 : firefox / nss (2026-7f6ee801e2)	Nessus	Fedora Local Security Checks	Local	critical
316445	Linux Distros Unpatched Vulnerability : CVE-2026-8963	Nessus	Misc.	Local	high
315985	Fedora 44 : firefox (2026-f3409cf313)	Nessus	Fedora Local Security Checks	Local	critical
315967	Fedora 43 : firefox / nss (2026-cd20332935)	Nessus	Fedora Local Security Checks	Local	critical
315434	Mozilla Thunderbird < 151.0	Nessus	MacOS X Local Security Checks	Local	critical
315432	Mozilla Thunderbird < 151.0	Nessus	Windows	Local	critical
315327	Mozilla Firefox < 151.0	Nessus	MacOS X Local Security Checks	Local	critical
315323	Mozilla Firefox < 151.0	Nessus	Windows	Local	critical

Detections

Analytics

CVE-2026-8963

high

Tenable Plugins

critical

critical

high

critical

critical

critical

critical

critical

critical