Buffer Overflow in libX11 <1.8.14 (XkbGetMap)
CVE-2026-88806 Published on September 21, 2026

libX11 XkbGetMap Reply Heap-based Buffer Overflow
A malicious X server could exploit a buffer overflow in libX11 before 1.8.14 during handling of XkbGetMap overflowing the key_sym_map.

NVD

Vulnerability Analysis

CVE-2026-88806 is exploitable with network access, requires user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.

Attack Vector:
NETWORK
Attack Complexity:
HIGH
Privileges Required:
NONE
User Interaction:
REQUIRED
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().


Products Associated with CVE-2026-88806

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Xorg Libx11
 
Canonical Ubuntu Linux
 

Affected Versions

x.org libX11: