CVE-2026-33999 Xorg: xwayland: x.org x server: denial of service via integer underflow in xkb compatibility map handling
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.
Problem types: cwe_id: CWE-191
description: Integer Underflow (Wrap or Wraparound)
Affected products: vendor: Red Hat
product: Red Hat Enterprise Linux 10
cpes: cpe:/o:redhat:enterprise_linux:10.1
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 10
cpes: cpe:/o:redhat:enterprise_linux:10.2
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 10.0 Extended Update Support
cpes: cpe:/o:redhat:enterprise_linux_eus:10.0
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 6 Extended Lifecycle Support  - EXTENSION
cpes: cpe:/o:redhat:rhel_els:6
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 7 Extended Lifecycle Support
cpes: cpe:/o:redhat:rhel_els:7
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 7 Extended Lifecycle Support
cpes: cpe:/o:redhat:rhel_els:7
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8
cpes: cpe:/a:redhat:enterprise_linux:8::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8
cpes: cpe:/a:redhat:enterprise_linux:8::appstream
cpe:/a:redhat:enterprise_linux:8::crb
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8
cpes: cpe:/a:redhat:enterprise_linux:8::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
cpes: cpe:/a:redhat:rhel_aus:8.4::appstream
cpe:/a:redhat:rhel_eus_long_life:8.4::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
cpes: cpe:/a:redhat:rhel_aus:8.4::appstream
cpe:/a:redhat:rhel_eus_long_life:8.4::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
cpes: cpe:/a:redhat:rhel_aus:8.4::appstream
cpe:/a:redhat:rhel_eus_long_life:8.4::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On
cpes: cpe:/a:redhat:rhel_aus:8.4::appstream
cpe:/a:redhat:rhel_eus_long_life:8.4::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
cpes: cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.6::appstream
cpe:/a:redhat:rhel_tus:8.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
cpes: cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.6::appstream
cpe:/a:redhat:rhel_tus:8.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support
cpes: cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_eus_long_life:8.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On
cpes: cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_eus_long_life:8.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.6 Telecommunications Update Service
cpes: cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.6::appstream
cpe:/a:redhat:rhel_tus:8.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.6 Telecommunications Update Service
cpes: cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.6::appstream
cpe:/a:redhat:rhel_tus:8.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.6::appstream
cpe:/a:redhat:rhel_tus:8.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_aus:8.6::appstream
cpe:/a:redhat:rhel_e4s:8.6::appstream
cpe:/a:redhat:rhel_tus:8.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.8 Telecommunications Update Service
cpes: cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_tus:8.8::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.8 Telecommunications Update Service
cpes: cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_tus:8.8::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.8 Telecommunications Update Service
cpes: cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_tus:8.8::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_tus:8.8::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_tus:8.8::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:8.8::appstream
cpe:/a:redhat:rhel_tus:8.8::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9
cpes: cpe:/a:redhat:enterprise_linux:9::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9
cpes: cpe:/a:redhat:enterprise_linux:9::appstream
cpe:/a:redhat:enterprise_linux:9::crb
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9
cpes: cpe:/a:redhat:enterprise_linux:9::appstream
cpe:/a:redhat:enterprise_linux:9::crb
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9
cpes: cpe:/a:redhat:enterprise_linux:9::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9
cpes: cpe:/a:redhat:enterprise_linux:9::appstream
cpe:/a:redhat:enterprise_linux:9::crb
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9
cpes: cpe:/a:redhat:enterprise_linux:9::appstream
cpe:/a:redhat:enterprise_linux:9::crb
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:9.0::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:9.0::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:9.0::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:9.2::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:9.2::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions
cpes: cpe:/a:redhat:rhel_e4s:9.2::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.4 Extended Update Support
cpes: cpe:/a:redhat:rhel_eus:9.4::appstream
cpe:/a:redhat:rhel_eus:9.4::crb
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.4 Extended Update Support
cpes: cpe:/a:redhat:rhel_eus:9.4::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.4 Extended Update Support
cpes: cpe:/a:redhat:rhel_eus:9.4::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.6 Extended Update Support
cpes: cpe:/a:redhat:rhel_eus:9.6::appstream
cpe:/a:redhat:rhel_eus:9.6::crb
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.6 Extended Update Support
cpes: cpe:/a:redhat:rhel_eus:9.6::appstream
cpe:/a:redhat:rhel_eus:9.6::crb
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 9.6 Extended Update Support
cpes: cpe:/a:redhat:rhel_eus:9.6::appstream
default_status: affected
vendor: Red Hat
product: Red Hat Enterprise Linux 6
cpes: cpe:/o:redhat:enterprise_linux:6
default_status: unknown
CVSS v3.1: attackComplexity: LOW
attackVector: LOCAL
availabilityImpact: HIGH
baseScore: 7.8
baseSeverity: HIGH
confidentialityImpact: HIGH
integrityImpact: HIGH
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
version: 3.1
Credits: lang: en
value: Red Hat would like to thank Jan-Niklas Sohn (TrendAI Zero Day Initiative) for reporting this issue.
Published: 2026-04-23T14:53:59.414Z