Mozilla Firefox ESR < 115.34

critical Nessus Plugin ID 303470

Synopsis

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

Description

The version of Firefox ESR installed on the remote macOS or Mac OS X host is prior to 115.34. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-21 advisory.

- JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9. (CVE-2026-4698)

- Sandbox escape in the Responsive Design Mode component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9. (CVE-2026-4692)

- Race condition, use-after-free in the Graphics: WebRender component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
(CVE-2026-4684)

- Incorrect boundary conditions in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
(CVE-2026-4685, CVE-2026-4686, CVE-2026-4706, CVE-2026-4707)

- Sandbox escape due to incorrect boundary conditions in the Telemetry component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9.
(CVE-2026-4687)

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 Firefox ESR version 115.34 or later.

See Also

https://www.mozilla.org/en-US/security/advisories/mfsa2026-21/

Plugin Details

Severity: Critical

ID: 303470

File Name: macos_firefox_115_34_esr.nasl

Version: 1.4

Type: Local

Agent: macosx

Published: 3/24/2026

Updated: 3/27/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-4698

CVSS v3

Risk Factor: Critical

Base Score: 10

Temporal Score: 8.7

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:U/RL:O/RC:C

CVSS Score Source: CVE-2026-4692

Vulnerability Information

CPE: cpe:/a:mozilla:firefox_esr

Required KB Items: installed_sw/Mozilla Firefox ESR

Exploit Ease: No known exploits are available

Patch Publication Date: 3/24/2026

Vulnerability Publication Date: 3/24/2026

Reference Information

CVE: CVE-2026-4684, CVE-2026-4685, CVE-2026-4686, CVE-2026-4687, CVE-2026-4689, CVE-2026-4690, CVE-2026-4691, CVE-2026-4692, CVE-2026-4693, CVE-2026-4694, CVE-2026-4696, CVE-2026-4698, CVE-2026-4699, CVE-2026-4706, CVE-2026-4707, CVE-2026-4709, CVE-2026-4721

IAVA: 2026-A-0274