Detections
Analytics

Mozilla Thunderbird < 154.0

critical Nessus Plugin ID 337889

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 154.0. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-78 advisory.

 - Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154 and Thunderbird 154. (CVE-2026-75874)

 - Site isolation issue in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74934)

 - Privilege escalation in the DOM: Networking component. This vulnerability was fixed in Firefox 154, Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1. (CVE-2026-74935)

 - Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
 (CVE-2026-74936)

 - Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1. (CVE-2026-74937)

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 154.0 or later.

See Also

https://www.mozilla.org/en-US/security/advisories/mfsa2026-78/

Plugin Details

Severity: Critical

ID: 337889

File Name: macos_thunderbird_154_0.nasl

Version: 1.1

Type: Local

Agent: macosx

Published: 8/19/2026

Updated: 8/19/2026

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: High

Score: 7

Percentile: 98.2

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-2026-75874

CVSS v3

Risk Factor: Critical

Base Score: 10

Temporal Score: 9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/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: 8/18/2026

Vulnerability Publication Date: 8/18/2026

Reference Information

CVE: CVE-2026-74934, CVE-2026-74935, CVE-2026-74936, CVE-2026-74937, CVE-2026-74938, CVE-2026-74939, CVE-2026-74940, CVE-2026-74941, CVE-2026-74942, CVE-2026-74943, CVE-2026-74944, CVE-2026-74945, CVE-2026-74946, CVE-2026-74947, CVE-2026-74948, CVE-2026-74949, CVE-2026-74950, CVE-2026-74952, CVE-2026-74953, CVE-2026-74954, CVE-2026-74955, CVE-2026-74956, CVE-2026-74957, CVE-2026-74958, CVE-2026-74959, CVE-2026-74960, CVE-2026-74961, CVE-2026-74962, CVE-2026-74963, CVE-2026-74964, CVE-2026-74965, CVE-2026-74966, CVE-2026-74967, CVE-2026-74968, CVE-2026-74969, CVE-2026-74970, CVE-2026-74971, CVE-2026-74972, CVE-2026-74973, CVE-2026-74974, CVE-2026-74976, CVE-2026-74977, CVE-2026-74978, CVE-2026-74979, CVE-2026-74981, CVE-2026-74982, CVE-2026-74983, CVE-2026-74984, CVE-2026-74985, CVE-2026-74986, CVE-2026-74987, CVE-2026-74988, CVE-2026-74989, CVE-2026-74990, CVE-2026-75874