Information disclosure, mitigation bypass in the Settings UI component. This vulnerability affects Firefox < 148 and Thunderbird < 148.

The remote Fedora 44 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-b5bde68630 advisory.

    Update NSS to 3.120.1     Update to Firefox 148.0

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 FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the 1124a7b0-1338-11f1-a55d-b42e991fc52e advisory.

    CVE-2026-2807: Memory safety bugs present in Firefox 147 and Thunderbird 147     CVE-2026-2806: Uninitialized memory in the Graphics: Text component.
    CVE-2026-2805: Invalid pointer in the DOM: Core & HTML component.
    CVE-2026-2804: Use-after-free in the JavaScript: WebAssembly component.
    CVE-2026-2803: Information disclosure, mitigation bypass in the Settings           UI component.
    CVE-2026-2802: Race condition in the JavaScript: GC component.
    CVE-2026-2801: Incorrect boundary conditions in the JavaScript:
          WebAssembly component.
    CVE-2026-2799: Use-after-free in the DOM: Core & HTML component.
    CVE-2026-2798: Use-after-free in the DOM: Core & HTML component.
    CVE-2026-2797: Use-after-free in the JavaScript: GC component.
    CVE-2026-2796: JIT miscompilation in the JavaScript: WebAssembly component     CVE-2026-2795: Use-after-free in the JavaScript: GC component.

Tenable has extracted the preceding description block directly from the FreeBSD 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 42 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-0709b275a5 advisory.

    Update NSS to 3.120.1     Update to Firefox 148.0

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.

  - Information disclosure, mitigation bypass in the Settings UI component. This vulnerability affects Firefox     < 148 and Thunderbird < 148. (CVE-2026-2803)

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

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-766e3a6ec8 advisory.

    - New upstream release (148.0)

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 Windows host is prior to 148.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-16 advisory.

  - Memory safety bugs present in Firefox 147 and Thunderbird 147. 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-2026-2807)

  - Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability     affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird <     140.8. (CVE-2026-2778)

  - Incorrect boundary conditions in the WebRTC: Audio/Video component. This vulnerability affects Firefox <     148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
    (CVE-2026-2757)

  - Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR <     115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8. (CVE-2026-2758)

  - Incorrect boundary conditions in the Graphics: ImageLib component. This vulnerability affects Firefox <     148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
    (CVE-2026-2759)

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 148.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-16 advisory.

  - Memory safety bugs present in Firefox 147 and Thunderbird 147. 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-2026-2807)

  - Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability     affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird <     140.8. (CVE-2026-2778)

  - Incorrect boundary conditions in the WebRTC: Audio/Video component. This vulnerability affects Firefox <     148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
    (CVE-2026-2757)

  - Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR <     115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8. (CVE-2026-2758)

  - Incorrect boundary conditions in the Graphics: ImageLib component. This vulnerability affects Firefox <     148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
    (CVE-2026-2759)

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 148.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-13 advisory.

  - Memory safety bugs present in Firefox 147 and Thunderbird 147. 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-2026-2807)

  - Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability     affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird <     140.8. (CVE-2026-2778)

  - Incorrect boundary conditions in the WebRTC: Audio/Video component. This vulnerability affects Firefox <     148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
    (CVE-2026-2757)

  - Information disclosure due to uninitialized memory in Firefox and Firefox Focus for Android. This     vulnerability affects Firefox < 148. (CVE-2026-2794)

  - Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR <     115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8. (CVE-2026-2758)

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 148.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-13 advisory.

  - Memory safety bugs present in Firefox 147 and Thunderbird 147. 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-2026-2807)

  - Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability     affects Firefox < 148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird <     140.8. (CVE-2026-2778)

  - Incorrect boundary conditions in the WebRTC: Audio/Video component. This vulnerability affects Firefox <     148, Firefox ESR < 115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8.
    (CVE-2026-2757)

  - Information disclosure due to uninitialized memory in Firefox and Firefox Focus for Android. This     vulnerability affects Firefox < 148. (CVE-2026-2794)

  - Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR <     115.33, Firefox ESR < 140.8, Thunderbird < 148, and Thunderbird < 140.8. (CVE-2026-2758)

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	Severity
301445	Fedora 44 : firefox / nss (2026-b5bde68630)	Nessus	Fedora Local Security Checks	critical
300606	FreeBSD : Firefox -- Multiple vulnerabilities (1124a7b0-1338-11f1-a55d-b42e991fc52e)	Nessus	FreeBSD Local Security Checks	critical
300500	Fedora 42 : firefox / nss (2026-0709b275a5)	Nessus	Fedora Local Security Checks	critical
300122	Linux Distros Unpatched Vulnerability : CVE-2026-2803	Nessus	Misc.	high
300114	Fedora 43 : firefox (2026-766e3a6ec8)	Nessus	Fedora Local Security Checks	critical
299891	Mozilla Thunderbird < 148.0	Nessus	Windows	critical
299889	Mozilla Thunderbird < 148.0	Nessus	MacOS X Local Security Checks	critical
299866	Mozilla Firefox < 148.0	Nessus	MacOS X Local Security Checks	critical
299865	Mozilla Firefox < 148.0	Nessus	Windows	critical

Detections

Analytics

CVE-2026-2803

high

Tenable Plugins

critical

critical

critical

high

critical

critical

critical

critical

critical