Detections
Analytics

Mozilla Thunderbird < 154.0

critical Nessus Plugin ID 337888

Synopsis

A mail client installed on the remote Windows host is affected by multiple vulnerabilities.

Description

The version of Thunderbird installed on the remote Windows 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: 337888

File Name: mozilla_thunderbird_154_0.nasl

Version: 1.1

Type: Local

Agent: windows

Family: Windows

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