Memory safety bugs present in Firefox 151 and Thunderbird 151. 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. This vulnerability was fixed in Firefox 152 and Thunderbird 152.

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-2fb5ca48a2 advisory.

    Update to latest upstream version

    ----

    Update to latest upstream version.

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 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-cda0c20ce0 advisory.

    Update to latest upstream version

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-2026-1c873954fa advisory.

    Update NSS to 3.124.0     Update to Firefox 152.0

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 44 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-5eeadd9b1b advisory.

    Update NSS to 3.124.0     Update Firefox to 152.0

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.

  - Memory safety bugs present in Firefox 151 and Thunderbird 151. 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. This vulnerability was fixed in Firefox 152 and Thunderbird 152. (CVE-2026-12326)

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 152.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-60 advisory.

  - Use-after-free in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and     Thunderbird 152. (CVE-2026-12293)

  - Privilege escalation in the Graphics: WebRender component. This vulnerability was fixed in Firefox 152,     Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12289)

  - Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12,     Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12290)

  - Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR     140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12291)

  - Incorrect boundary conditions in the Web Audio component. This vulnerability was fixed in Firefox 152,     Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12292)

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 152.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-60 advisory.

  - Use-after-free in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and     Thunderbird 152. (CVE-2026-12293)

  - Privilege escalation in the Graphics: WebRender component. This vulnerability was fixed in Firefox 152,     Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12289)

  - Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12,     Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12290)

  - Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR     140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12291)

  - Incorrect boundary conditions in the Web Audio component. This vulnerability was fixed in Firefox 152,     Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12292)

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 152.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-57 advisory.

  - Use-after-free in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and     Thunderbird 152. (CVE-2026-12293)

  - Privilege escalation in the Graphics: WebRender component. This vulnerability was fixed in Firefox 152,     Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12289)

  - Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12,     Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12290)

  - Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR     140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12291)

  - Incorrect boundary conditions in the Web Audio component. This vulnerability was fixed in Firefox 152,     Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12292)

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 152.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-57 advisory.

  - Use-after-free in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 152 and     Thunderbird 152. (CVE-2026-12293)

  - Privilege escalation in the Graphics: WebRender component. This vulnerability was fixed in Firefox 152,     Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12289)

  - Memory safety bug fixed in Firefox 152. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12,     Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12290)

  - Use-after-free in the Networking: HTTP component. This vulnerability was fixed in Firefox 152, Firefox ESR     140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12291)

  - Incorrect boundary conditions in the Web Audio component. This vulnerability was fixed in Firefox 152,     Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12. (CVE-2026-12292)

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
324624	Fedora 43 : thunderbird (2026-2fb5ca48a2)	Nessus	Fedora Local Security Checks	Local	critical
323139	Fedora 44 : thunderbird (2026-cda0c20ce0)	Nessus	Fedora Local Security Checks	Local	critical
321672	Fedora 43 : firefox / nss (2026-1c873954fa)	Nessus	Fedora Local Security Checks	Local	critical
321470	Fedora 44 : firefox / nss (2026-5eeadd9b1b)	Nessus	Fedora Local Security Checks	Local	critical
321417	Linux Distros Unpatched Vulnerability : CVE-2026-12326	Nessus	Misc.	Local	high
321222	Mozilla Thunderbird < 152.0	Nessus	MacOS X Local Security Checks	Local	critical
321220	Mozilla Thunderbird < 152.0	Nessus	Windows	Local	critical
321196	Mozilla Firefox < 152.0	Nessus	Windows	Local	critical
321194	Mozilla Firefox < 152.0	Nessus	MacOS X Local Security Checks	Local	critical

Detections

Analytics

CVE-2026-12326

high

Tenable Plugins

critical

critical

critical

critical

high

critical

critical

critical

critical