CVE-2026-33999
Published:April 23, 2026
Updated:May 18, 2026
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.
Affected Packages
https://github.com/external-mirrors/xorg-xserver.git (GITHUB):
Affected version(s) >=xorg-server-0_99_1 <xorg-server-21.1.22Fix Suggestion:
Update to version xorg-server-21.1.22https://github.com/external-mirrors/xorg-xserver.git (GITHUB):
Affected version(s) >=xwayland-24.1.0 <xwayland-24.1.10Fix Suggestion:
Update to version xwayland-24.1.10Related Resources (9)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.5
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.8
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Integer Underflow (Wrap or Wraparound)
EPSS
Base Score:
0.01