---
id: "CVE-2026-109089"
kind: "vulnerability"
aliases: ["CVE-2026-109089"]
title: "libXi: heap buffer overflow in DEVICE_RESOLUTION handling from malicious X server"
severity: "high"
cvss: 7.5
epss: null
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["desktop", "infrastructure", "libxi", "linux", "x11"]
not_affected_if: ["no-x11-clients", "wayland-only"]
published_at: "2026-10-27T17:16:57+00:00"
first_seen_at: "2026-10-27T17:32:45+00:00"
updated_at: "2026-10-27T17:34:39+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109089", "first_seen_at": "2026-10-27T17:32:45+00:00"}]
---

# libXi: heap buffer overflow in DEVICE_RESOLUTION handling from malicious X server

libXi versions before 1.8.4 contain a buffer overflow when parsing DEVICE_RESOLUTION replies, which can overflow a heap buffer. A malicious X server can trigger it, which may let an attacker corrupt memory in the client program.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- `xdpyinfo` or `pkg-config --modversion xi` to find the installed libXi version
- Check the installed libXi package with your OS package manager, for example `dpkg -l libxi6` or `rpm -q libXi`

## Fix

- Upgrade libXi to `1.8.4` or later through your OS package manager
- Rebuild dependent applications that link statically against libXi

## Timeline

- 2026-10-27T17:32:45+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-109089

## From the sources

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

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_