High severity · published Oct 28, 2026
CVE-2026-93520
X.Org Server XKB ChangeKeycodeRange Heap Out-of-Bounds Write
New
7.8
CVSS
–
EPSS
No
On KEV
Description
A heap buffer overflow caused by mismatching size calculations between XkbAllocNames and ChangeKeycodeRange in X.org X server before 2.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to crash or potentially execute code in X server context.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
XO
xorg-x11-server · x.org
before 21.1.25 · source: vendor
XW
xwayland · x.org
before 24.1.14 · source: vendor
In the news
VulnerabilityHigh
ZDI-26-765: X.Org Server XKB Heap-based Buffer Overflow Privilege Escalation Vulnerability
This vulnerability allows local attackers to escalate privileges on affected installations of X.Org Server. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-93520.
Oct 15, 2026·Zero Day Initiative
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-93520
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-93520
patch
https://gitlab.freedesktop.org/xorg/xserver/-/commit/b941a473e06f26a407a9adb15759be79f7418e86
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