RHEL 9 : thunderbird (RHSA-2026:77632)

critical Nessus Plugin ID 364145

Synopsis

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

Description

The remote Redhat Enterprise Linux 9 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2026:77632 advisory.

Mozilla Thunderbird is a standalone mail and newsgroup client.

Security Fix(es):

* firefox: thunderbird: Privilege escalation in the DOM: Workers component (CVE-2026-16365)

* firefox: thunderbird: Sandbox escape in the Remote Settings Client component (CVE-2026-75874)

* firefox: Sandbox escape due to use-after-free in the DOM: Security component (CVE-2026-84121)

* firefox: Internally found bugs fixed in Firefox 155, Firefox ESR 153.2, Firefox ESR 140.15 and Firefox ESR 115.40 (CVE-2026-84145)

* firefox: Sandbox escape due to use-after-free in the DOM: Navigation component (CVE-2026-84119)

* firefox: Use-after-free in the Audio/Video component (CVE-2026-84120)

* firefox: Privilege escalation due to invalid pointer in the Graphics component (CVE-2026-84131)

* firefox: Use-after-free in the DOM: Core & HTML component (CVE-2026-84124)

* firefox: Use-after-free in the Audio/Video component (CVE-2026-84122)

* firefox: Internally found bugs fixed in Firefox 155, Firefox ESR 153.2 and Firefox ESR 140.15 (CVE-2026-84143)

* thunderbird: Uninitialized memory in MIME parsing (CVE-2026-84639)

* thunderbird: Information disclosure due to malicious IMAP server response (CVE-2026-84641)

* thunderbird: One byte overflow read in mail parser (CVE-2026-84640)

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 thunderbird package based on the guidance in RHSA-2026:77632.

Plugin Details

Severity: Critical

ID: 364145

File Name: redhat-RHSA-2026-77632.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 10/8/2026

Updated: 10/8/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.74

Vendor

Vendor Severity: Important

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-2026-84143

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:redhat:rhel_e4s:9.2, p-cpe:/a:redhat:enterprise_linux:thunderbird

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/8/2026

Vulnerability Publication Date: 7/21/2026

Reference Information

CVE: CVE-2026-16365, CVE-2026-75874, CVE-2026-84119, CVE-2026-84120, CVE-2026-84121, CVE-2026-84122, CVE-2026-84124, CVE-2026-84131, CVE-2026-84143, CVE-2026-84145, CVE-2026-84639, CVE-2026-84640, CVE-2026-84641

CWE: 125, 266, 653, 787, 824, 825

RHSA: 2026:77632

Detections

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