Detections
Analytics

Mozilla Firefox ESR < 115.39

critical Nessus Plugin ID 337623

Language:

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 115.39. It is, therefore, affected by multiple vulnerabilities as referenced in the mfsa2026-75 advisory.

 - Internally found bugs present in Firefox ESR 115.38, Firefox ESR 140.13, Firefox ESR 153.0 and Firefox 153. 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-2026-74990)

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 115.39 or later.

See Also

https://www.mozilla.org/en-US/security/advisories/mfsa2026-75/

Plugin Details

Severity: Critical

ID: 337623

File Name: macos_firefox_115_39_esr.nasl

Version: 1.4

Type: Local

Agent: macosx

Published: 8/18/2026

Updated: 8/24/2026

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: 96.61

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-2026-74943

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:firefox_esr

Required KB Items: installed_sw/Mozilla Firefox ESR

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-2026-74939, CVE-2026-74940, CVE-2026-74942, CVE-2026-74943, CVE-2026-74945, CVE-2026-74946, CVE-2026-74948, CVE-2026-74969, CVE-2026-74973, CVE-2026-74974, CVE-2026-74990

IAVA: 2026-A-0876