RHEL 9 : xorg-x11-server (RHSA-2026:84574)

high Nessus Plugin ID 367210

Synopsis

The remote Red Hat host is missing one or more security updates for xorg-x11-server.

Description

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:84574 advisory.

X.Org is an open-source implementation of the X Window System. It provides the basic low-level functionality that full-fledged graphical user interfaces are designed upon.

Security Fix(es):

* xorg-x11-server: xorg-x11-server: Arbitrary code execution via use-after-free in passive grab handling (CVE-2026-93516)

* xorg-x11-server: xorg-x11-server: arbitrary code execution via GLX RenderLarge heap-based buffer overflow (CVE-2026-93517)

* xorg-x11-server: xorg-x11-server: arbitrary code execution via integer truncation during keyboard mapping resize (CVE-2026-93518)

* xorg-x11-server: xorg-x11-server: Arbitrary code execution via buffer overflow in input_constrain_cursor() (CVE-2026-93519)

* xorg-x11-server: xorg-x11-server: arbitrary code execution via out-of-bounds write in XKB keycode handling (CVE-2026-93520)

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 xorg-x11-server package based on the guidance in RHSA-2026:84574.

See Also

https://access.redhat.com/errata/RHSA-2026:84574

https://access.redhat.com/security/updates/classification/#important

https://bugzilla.redhat.com/show_bug.cgi?id=2545161

https://bugzilla.redhat.com/show_bug.cgi?id=2545246

https://bugzilla.redhat.com/show_bug.cgi?id=2545860

https://bugzilla.redhat.com/show_bug.cgi?id=2545887

https://bugzilla.redhat.com/show_bug.cgi?id=2545908

http://www.nessus.org/u?e0f270ac

Plugin Details

Severity: High

ID: 367210

File Name: redhat-RHSA-2026-84574.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 10/19/2026

Updated: 10/19/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.38

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-93520

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/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:enterprise_linux:9, cpe:/o:redhat:rhel_eus:9.8, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server-common, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server-devel, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server-source, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server-xdmx, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server-xephyr, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server-xnest, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server-xorg, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server-xvfb, p-cpe:/a:redhat:enterprise_linux:xorg-x11-server

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: 10/19/2026

Vulnerability Publication Date: 10/7/2026

Reference Information

CVE: CVE-2026-93516, CVE-2026-93517, CVE-2026-93518, CVE-2026-93519, CVE-2026-93520

CWE: 120, 787, 825

RHSA: 2026:84574