Detections
Analytics

Mozilla Firefox ESR < 140.8

high Nessus Plugin ID 299870

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 140.8. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-15 advisory.

 - Memory safety bugs present in Firefox ESR 115.32, Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. (CVE-2026-2793)

 - Incorrect boundary conditions in the WebRTC: Audio/Video component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8. (CVE-2026-2757)

 - Use-after-free in the JavaScript: GC component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8. (CVE-2026-2758)

 - Incorrect boundary conditions in the Graphics: ImageLib component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8. (CVE-2026-2759)

 - Sandbox escape due to incorrect boundary conditions in the Graphics: WebRender component. This vulnerability affects Firefox < 148, Firefox ESR < 115.33, and Firefox ESR < 140.8. (CVE-2026-2760)

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 140.8 or later.

See Also

https://www.mozilla.org/en-US/security/advisories/mfsa2026-15/

Plugin Details

Severity: High

ID: 299870

File Name: macos_firefox_140_8_esr.nasl

Version: 1.1

Type: local

Agent: macosx

Published: 2/24/2026

Updated: 2/24/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.3

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-2793

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

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

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

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: 2/24/2026

Vulnerability Publication Date: 2/24/2026

Reference Information

CVE: CVE-2026-2757, CVE-2026-2758, CVE-2026-2759, CVE-2026-2760, CVE-2026-2761, CVE-2026-2762, CVE-2026-2763, CVE-2026-2764, CVE-2026-2765, CVE-2026-2766, CVE-2026-2767, CVE-2026-2768, CVE-2026-2769, CVE-2026-2770, CVE-2026-2771, CVE-2026-2772, CVE-2026-2773, CVE-2026-2774, CVE-2026-2775, CVE-2026-2776, CVE-2026-2777, CVE-2026-2778, CVE-2026-2779, CVE-2026-2780, CVE-2026-2781, CVE-2026-2782, CVE-2026-2783, CVE-2026-2784, CVE-2026-2785, CVE-2026-2786, CVE-2026-2787, CVE-2026-2788, CVE-2026-2789, CVE-2026-2790, CVE-2026-2791, CVE-2026-2792, CVE-2026-2793