RHEL 8 : firefox (RHSA-2026:58898)

critical Nessus Plugin ID 339104

Synopsis

The remote Red Hat host is missing one or more security updates for firefox.

Description

The remote Redhat Enterprise Linux 8 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2026:58898 advisory.

Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability.

Security Fix(es):

* firefox: thunderbird: Mitigation bypass in the Data Loss Prevention component (CVE-2026-74983)

* firefox: thunderbird: Site isolation issue in the Graphics: CanvasWebGL component (CVE-2026-74934)

* firefox: thunderbird: Privilege escalation in the Networking: Cookies component (CVE-2026-74953)

* firefox: thunderbird: Internally found bugs fixed in Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154 (CVE-2026-74987)

* firefox: thunderbird: Information disclosure in the Graphics component (CVE-2026-74948)

* firefox: thunderbird: Use-after-free in the Graphics: ImageLib component (CVE-2026-74943)

* firefox: thunderbird: Information disclosure in the DOM: UI Events & Focus Handling component (CVE-2026-74971)

* firefox: thunderbird: Privilege escalation in the Graphics: CanvasWebGL component (CVE-2026-74941)

* firefox: Privilege escalation in the Shell Integration component (CVE-2026-74965)

* firefox: thunderbird: Privilege escalation due to incorrect boundary conditions in the Graphics:
CanvasWebGL component (CVE-2026-74946)

* firefox: Race condition, use-after-free in the Graphics component (CVE-2026-74973)

* firefox: thunderbird: Privilege escalation due to use-after-free in the Graphics: Canvas2D component (CVE-2026-74949)

* firefox: thunderbird: Internally found bugs fixed in Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154 (CVE-2026-74990)

* firefox: thunderbird: Use-after-free in the JavaScript: WebAssembly component (CVE-2026-74936)

* firefox: thunderbird: Use-after-free in the Graphics: Text component (CVE-2026-74940)

* firefox: thunderbird: Site isolation issue in the WebExtensions component (CVE-2026-74960)

* firefox: thunderbird: Use-after-free in the Layout: Text and Fonts component (CVE-2026-74969)

* firefox: thunderbird: Mitigation bypass in the Storage: Cache API component (CVE-2026-74959)

* firefox: thunderbird: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-74976)

* firefox: thunderbird: Same-origin policy bypass in the Graphics: ImageLib component (CVE-2026-74974)

* firefox: thunderbird: Mitigation bypass in the Safe Browsing component (CVE-2026-74957)

* firefox: thunderbird: Same-origin policy bypass in the Audio/Video: Playback component (CVE-2026-74967)

* firefox: Privilege escalation in the Remote Settings Client component (CVE-2026-74942)

* firefox: thunderbird: Privilege escalation in the DOM: Navigation component (CVE-2026-74939)

* firefox: thunderbird: Information disclosure in the DOM: Push Subscriptions component (CVE-2026-74972)

* firefox: thunderbird: Information disclosure in the Graphics: Text component (CVE-2026-74945)

* firefox: thunderbird: Same-origin policy bypass in the Networking: Cookies component (CVE-2026-74963)

* firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-74944)

* firefox: Integer overflow in the Graphics component (CVE-2026-74964)

* firefox: Site isolation issue in the Networking: Cookies component (CVE-2026-74962)

* firefox: thunderbird: Privilege escalation in the DOM: Networking component (CVE-2026-74935)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL firefox package based on the guidance in RHSA-2026:58898.

Plugin Details

Severity: Critical

ID: 339104

File Name: redhat-RHSA-2026-58898.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 8/24/2026

Updated: 8/24/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.19

Vendor

Vendor Severity: Important

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-2026-74944

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:/o:redhat:enterprise_linux:8, cpe:/o:redhat:rhel_eus:8.10, p-cpe:/a:redhat:enterprise_linux:firefox

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/24/2026

Vulnerability Publication Date: 8/18/2026

Reference Information

CVE: CVE-2026-74934, CVE-2026-74935, CVE-2026-74936, 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-2026-74948, CVE-2026-74949, CVE-2026-74953, CVE-2026-74957, CVE-2026-74959, CVE-2026-74960, CVE-2026-74962, CVE-2026-74963, CVE-2026-74964, CVE-2026-74965, CVE-2026-74967, CVE-2026-74969, CVE-2026-74971, CVE-2026-74972, CVE-2026-74973, CVE-2026-74974, CVE-2026-74976, CVE-2026-74983, CVE-2026-74987, CVE-2026-74990

CWE: 1100, 190, 201, 266, 346, 360, 472, 497, 501, 653, 733, 787, 807, 825, 940

RHSA: 2026:58898

Detections

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