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CVE-2026-33999

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

Published: Apr 23, 2026Updated: Jun 8, 2026 Sources: CVE List NVD BDUCWE-191
NVD MITRE
7.8CVSSHIGH
EPSS Score
0.2%
Top 92.4%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available

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.

CVSS Vector Breakdown

AV:LAC:LPR:LUI:NS:UC:HI:HA:H
Exploitability
AV:LAttack Vector
Local
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
Open in CVSS calculator →

Weaknesses

CWE-191

Affected Products

Red Hat Enterprise LinuxRed Hat Inc.
On-premOS
Operating Systems / linux-distro
X.Org ServerX.Org FoundationOperating Systems / unix-bsd
XWaylandСообщество свободного программного обеспечения
On-prem
Operating Systems / linux-distro
Red Hat Enterprise Linux 10Red Hat
On-premOS
Operating Systems / linux-distro
Red Hat Enterprise Linux 10.0 Extended Update SupportRed Hat
On-premOS
Operating Systems / linux-distro
red hat inc.commercialUSOperating Systemsaka red hat
x.org foundationoss-projectUSOperating Systemsaka xorg-server, xlib, libx11
сообщество свободного программного обеспеченияoss-projectOperating Systemsaka сообщество свободного программного обеспечения, fsf
red hatcommercialUSOperating Systemsaka red hat
and 17 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

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Exploitability

Official Patch Available
Workaround Available

MITRE ATT&CK

1 technique
Initial Access
View detailed technique mapping

References

https://access.redhat.com/errata/RHSA-2026:10739
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:11352
access.redhat.com
https://access.redhat.com/errata/RHSA-2026:11369
access.redhat.com
and 39 more references View all →

Timeline

Published
Apr 23, 2026
Last Updated
Jun 8, 2026

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