XKB Double Free in X.Org X Server <21.1.25 & XWayland <24.1.14
CVE-2026-88812 Published on October 27, 2026
X.Org Server XKB SetGeometry TextDoodad Double Free
A double free in XKB SetGeometryin X.Org X Server before 21.1.25 and X Wayland before 24.1.14 could be used by attached clients to cause a crash or potentially code in the x server context.
Vulnerability Analysis
CVE-2026-88812 is exploitable with local system access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Type
What is a Double-free Vulnerability?
The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. When a program calls free() twice with the same argument, the program's memory management data structures become corrupted. This corruption can cause the program to crash or, in some circumstances, cause two later calls to malloc() to return the same pointer. If malloc() returns the same value twice and the program later gives the attacker control over the data that is written into this doubly-allocated memory, the program becomes vulnerable to a buffer overflow attack.
CVE-2026-88812 has been classified to as a Double-free vulnerability or weakness.
Products Associated with CVE-2026-88812
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Affected Versions
X.org xorg-x11-server:- Before 21.1.25 is affected.
- Before 24.1.14 is affected.