CVE-2026-33999

HIGH

Xorg: xwayland: x.org x server: denial of service via integer underflow in xkb compatibility map handling

Title source: cna

Description

A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of service (DoS) or other severe impacts.

References (37)

Core 37

Core References

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20575

https://access.redhat.com/errata/RHSA-2026:20575

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20576

https://access.redhat.com/errata/RHSA-2026:20576

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20590

https://access.redhat.com/errata/RHSA-2026:20590

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:22456

https://access.redhat.com/errata/RHSA-2026:22456

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:23254

https://access.redhat.com/errata/RHSA-2026:23254

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:23255

https://access.redhat.com/errata/RHSA-2026:23255

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:21699

https://access.redhat.com/errata/RHSA-2026:21699

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:21712

https://access.redhat.com/errata/RHSA-2026:21712

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:21715

https://access.redhat.com/errata/RHSA-2026:21715

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:21716

https://access.redhat.com/errata/RHSA-2026:21716

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:21718

https://access.redhat.com/errata/RHSA-2026:21718

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:21741

https://access.redhat.com/errata/RHSA-2026:21741

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:21742

https://access.redhat.com/errata/RHSA-2026:21742

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:22424

https://access.redhat.com/errata/RHSA-2026:22424

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:23496

https://access.redhat.com/errata/RHSA-2026:23496

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:24341

https://access.redhat.com/errata/RHSA-2026:24341

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:10739

https://access.redhat.com/errata/RHSA-2026:10739

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:11656

https://access.redhat.com/errata/RHSA-2026:11656

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:11692

https://access.redhat.com/errata/RHSA-2026:11692

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:11352

https://access.redhat.com/errata/RHSA-2026:11352

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:11369

https://access.redhat.com/errata/RHSA-2026:11369

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:11388

https://access.redhat.com/errata/RHSA-2026:11388

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:13414

https://access.redhat.com/errata/RHSA-2026:13414

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:19125

https://access.redhat.com/errata/RHSA-2026:19125

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:19342

https://access.redhat.com/errata/RHSA-2026:19342

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:19343

https://access.redhat.com/errata/RHSA-2026:19343

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:19344

https://access.redhat.com/errata/RHSA-2026:19344

Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat

https://access.redhat.com/security/cve/CVE-2026-33999

Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat

RHBZ#2451106

https://bugzilla.redhat.com/show_bug.cgi?id=2451106

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20547

https://access.redhat.com/errata/RHSA-2026:20547

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20555

https://access.redhat.com/errata/RHSA-2026:20555

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20557

https://access.redhat.com/errata/RHSA-2026:20557

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20558

https://access.redhat.com/errata/RHSA-2026:20558

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20560

https://access.redhat.com/errata/RHSA-2026:20560

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20561

https://access.redhat.com/errata/RHSA-2026:20561

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20562

https://access.redhat.com/errata/RHSA-2026:20562

Vendor Advisory vendor-advisory x_refsource_redhat

RHSA-2026:20563

https://access.redhat.com/errata/RHSA-2026:20563

Scores

CVSS v3 7.8

EPSS 0.0019

EPSS Percentile 9.2%

Attack Vector LOCAL

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CISA SSVC

Vulnrichment

Exploitation none

Automatable no

Technical Impact total

Details

CWE

CWE-191

Status published

Products (50)

Red Hat/Red Hat Enterprise Linux 10

Red Hat/Red Hat Enterprise Linux 10 0:24.1.5-6.el10_1

Red Hat/Red Hat Enterprise Linux 10 0:24.1.9-4.el10_2

Red Hat/Red Hat Enterprise Linux 10.0 Extended Update Support 0:24.1.5-6.el10_0

Red Hat/Red Hat Enterprise Linux 6

Red Hat/Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION 0:1.1.0-25.el6_10.16

Red Hat/Red Hat Enterprise Linux 7

Red Hat/Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:1.20.4-34.el7_9

Red Hat/Red Hat Enterprise Linux 7 Extended Lifecycle Support 0:1.8.0-36.el7_9.4

Red Hat/Red Hat Enterprise Linux 8

... and 40 more

Published Apr 23, 2026

Tracked Since Apr 23, 2026