The version of Thunderbird installed on the remote macOS or Mac OS X host is prior to 153.6. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-122 advisory.

  - Privilege escalation in the DLL Services component. This vulnerability was fixed in Firefox ESR 153.4,     Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 159, Firefox ESR 153.6, Thunderbird 159,     Thunderbird 153.6, Firefox 157, and Firefox ESR 140.17. (CVE-2026-100801)

  - When a message containing an OpenPGP key attachment was displayed, Thunderbird automatically loaded the     attachment's content to offer importing the key. A sender could mark the attachment as an external     attachment pointing to an arbitrary URL, which Thunderbird then loaded without any user interaction,     bypassing remote content blocking. On Windows, a URL pointing to an attacker-controlled network share     could leak the user's NTLM credentials.  The NTLM credential leak only affects Thunderbird on Windows. On     other operating systems, the issue allowed a remote request that bypassed remote content blocking.
    (CVE-2026-118174)

  - When replying to, forwarding, or editing a crafted email message as new, Thunderbird could embed parts of     a different message stored in the same folder into the message being composed, without showing a blocked     content warning. If the user sent the message, the content of the other message was disclosed to the     recipients. (CVE-2026-118175)

  - Thunderbird's check that prevents mailbox: URLs from accessing files on remote Windows network shares     could be bypassed using extended-length UNC paths. Displaying a specially crafted email could cause     Thunderbird to connect to an SMB server chosen by the attacker, disclosing the user's Windows account name     and NTLM authentication data, which could be used for offline password cracking or relay attacks.  This     bug only affects Thunderbird on Windows. Other operating systems are unaffected. (CVE-2026-118176)

  - When looking for calendars in a directory on a server, during account setup or when adding a new network     calendar, Thunderbird accepted calendar locations pointing to other servers, local files or network     shares. A malicious server, or a network attacker when the lookup used plain HTTP, could make Thunderbird     subscribe to such a location. On Windows this could leak the user's NTLM credentials to an attacker-     controlled host on every calendar refresh, and changes to the calendar could be written to the attacker's     share or overwrite a local file. (CVE-2026-118177)

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 153.6. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-120 advisory.

  - Privilege escalation in the DLL Services component. This vulnerability was fixed in Firefox ESR 153.4,     Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 159, Firefox ESR 153.6, Thunderbird 159,     Thunderbird 153.6, Firefox 157, and Firefox ESR 140.17. (CVE-2026-100801)

  - Same-origin policy bypass in the DOM: Navigation component. This vulnerability was fixed in Firefox 159,     Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6. (CVE-2026-117860)

  - Sandbox escape in the DOM: Navigation component. This vulnerability was fixed in Firefox 159, Firefox ESR     153.6, Thunderbird 159, and Thunderbird 153.6. (CVE-2026-117861)

  - Privilege escalation due to incorrect boundary conditions in the Networking component. This vulnerability     was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
    (CVE-2026-117862)

  - Information disclosure due to uninitialized memory in the Audio/Video component. This vulnerability was     fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.
    (CVE-2026-117863)

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.

  - Incorrect boundary conditions in the XML component. This vulnerability was fixed in Firefox 159, Firefox     ESR 153.6, Thunderbird 159, and Thunderbird 153.6. (CVE-2026-117945)

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

The remote Fedora 45 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-40997bb156 advisory.

    - Updated to latest upstream (159.0)

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 Oracle Linux 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the ELSA-2026-93956 advisory.

    [153.6.0-1.0.1]
    - Fix firefox-oracle-default-prefs.js for new nss [Orabug: 37079773]
    - Add firefox-oracle-default-prefs.js and remove the corresponding Red Hat file

    [153.6.0-1]
    - Update to 153.6.0 ESR

Tenable has extracted the preceding description block directly from the Oracle Linux 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	Name	Product	Family	Published	Updated	Severity
372624	Mozilla Thunderbird < 153.6	Nessus	MacOS X Local Security Checks	10/27/2026	11/6/2026	critical
372629	Mozilla Firefox ESR < 153.6	Nessus	MacOS X Local Security Checks	10/27/2026	11/6/2026	critical
372872	Linux Distros Unpatched Vulnerability : CVE-2026-117945	Nessus	Misc.	10/28/2026	11/6/2026	critical
374673	Fedora 45 : firefox (2026-40997bb156)	Nessus	Fedora Local Security Checks	10/31/2026	11/6/2026	critical
376147	Oracle Linux 10 : firefox (ELSA-2026-93956)	Nessus	Oracle Linux Local Security Checks	11/4/2026	11/6/2026	critical

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