CVE-2026-33999CWE-191

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

High · published April 23, 2026

CVSS v3.1
7.8
EPSS
0%
Percentile
7.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.8 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00186 · 7.8th percentile
Weakness
CWE-191 · Integer Underflow (Wrap or Wraparound)
Published
2026-04-23T14:53Z
EPSS history
Timeline
  • 23 APR 14:53Z
    Xorg: xwayland: x.org x server: denial of service via integer underflow in xkb compatibility map handling
    cvelistv5