Cloudanix VulnDB

CVE-2026-109089

High · 7.5

CVSS

7.5

EPSS

0.3%

Published

Oct 27, 2026

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A recently found flaw in a graphics input library could let attackers take control of computers if the system connects to a malicious display server.

Exploitation
Requires User Interaction
Attacker needs
User Interaction
Complexity
Moderate
Impact
Remote Code Execution
Component
Library
Class
Buffer Overflow
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Heap buffer overflow triggered during DEVICE_RESOLUTION handling in libXi, allowing memory corruption from a malicious X server response.

Why it matters to the business

Newly disclosed flaw in a core X11 input library could enable remote code execution or application crashes on systems using graphical interfaces, requiring urgent patching across Linux and Unix-like environments with X11 dependencies.

How an attack unfolds

An attacker hosts or compromises an X server that responds to DEVICE_RESOLUTION queries with oversized data, causing the client-side libXi library to overflow a heap buffer and potentially execute arbitrary code.

How to fix it

Upgrade libXi to version 1.8.4 or later; rebuild and redeploy any dependent X11 client applications; apply vendor patches for the full X server stack.

How to confirm the fix worked

Verify installed libXi version is 1.8.4 or newer via package manager or library inspection; monitor for application crashes or unexpected behavior during X server interactions; test connectivity against known-safe X servers.

Typical attack path

  1. Establish connection to a malicious or compromised X server
  2. Trigger XInput extension queries that invoke DEVICE_RESOLUTION handling
  3. Supply crafted oversized data to overflow the heap buffer
  4. Leverage memory corruption to achieve code execution or denial of service

How to detect it

Inspect system logs for X server connection anomalies or crashes in XInput-related processes; review library load paths and version strings in running applications.

What your security team should do

  • Prioritize upgrade of libXi to 1.8.4 across all affected systems within 30 days
  • Review and restrict X server connections to trusted sources only
  • Update inventory of X11-dependent packages and schedule regression testing after patching

The record

A buffer overflow when handling DEVICE_RESOLUTION in libXi before 1.8.4 could overflow a heap, triggered by a malicious X server.

Affected packages

Ecosystem Package Introduced Fixed

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