Heap Buffer Overflow in X.org X Server and XWayland Due to Integer Truncation Issue
CVE-2026-93518

7.8HIGH

Key Information:

Vendor

X.org

Status
Xorg-x11-server
Xwayland
Vendor
CVE Published:
28 October 2026

What is CVE-2026-93518?

An integer truncation vulnerability exists in the XkbResizeKeyType() function within the X.org X server and XWayland. This flaw permits authenticated X clients to exploit the system by potentially leading to a heap buffer overflow. This could result in crashes of the X server or allow unauthorized code execution, emphasizing the importance of updating affected versions to safeguard against such risks.

Affected Version(s)

xorg-x11-server 0 < 21.1.25

xwayland 0 < 24.1.14

References

https://gitlab.freedesktop.org/xorg/xserver/-/commit/8910...
patch

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Anonymous working with TrendAI Zero Day Initiative
.