Detections
Analytics

Mozilla Thunderbird < 153.2

critical Nessus Plugin ID 342260

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Synopsis

A mail client installed on the remote macOS or Mac OS X host is affected by multiple vulnerabilities.

Description

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.

 - Internally found bugs present in Thunderbird 154, Thunderbird ESR 153.1 and Thunderbird ESR 140.14. 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-2026-84143, CVE-2026-84145)

 - 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)

 - 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)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Upgrade to Mozilla Thunderbird version 153.2 or later.

See Also

https://www.mozilla.org/en-US/security/advisories/mfsa2026-88/

Plugin Details

Severity: Critical

ID: 342260

File Name: macos_thunderbird_153_2.nasl

Version: 1.5

Type: Local

Agent: macosx

Published: 9/1/2026

Updated: 10/21/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.5

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-84143

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:mozilla:thunderbird

Required KB Items: installed_sw/Mozilla Thunderbird

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/1/2026

Vulnerability Publication Date: 8/18/2026

Reference Information

CVE: CVE-2026-74952, CVE-2026-75874, CVE-2026-84118, CVE-2026-84119, CVE-2026-84120, CVE-2026-84121, CVE-2026-84122, CVE-2026-84123, CVE-2026-84124, CVE-2026-84125, CVE-2026-84129, CVE-2026-84130, CVE-2026-84131, CVE-2026-84132, CVE-2026-84133, CVE-2026-84134, CVE-2026-84136, CVE-2026-84137, CVE-2026-84139, CVE-2026-84140, CVE-2026-84141, CVE-2026-84143, CVE-2026-84144, CVE-2026-84145, CVE-2026-84637, CVE-2026-84639, CVE-2026-84640, CVE-2026-84641, CVE-2026-84642

IAVA: 2026-A-0877, 2026-A-0929