---
id: CVE-2026-93542
title: >-
  An out-of-bounds read in libXi's XI2 class parsing via size_classes() and
  copy_classes() in libXi before 1.8.4 could be used by malicous servers to
  crash the X client.
summary: >-
  An out-of-bounds read in libXi's XI2 class parsing via size_classes() and
  copy_classes() in libXi before 1.8.4 could be used by malicous servers to
  crash the X client.
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-125
vendor: x.org
product: libXi
affected:
  - libXi < 1.8.4
published: '2026-09-24'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:00:46.893'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93542'
references:
  - url: >-
      https://gitlab.freedesktop.org/xorg/lib/libxi/-/merge_requests/23/diffs?commit_id=f499944ad595b9bd7e7571c810842244caf150aa
    label: meissner@suse.de
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93542.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-93542'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2540477'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-93542'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93542'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-24T17:18:15.511330Z'
ingestedAt: '2026-09-24T16:47:15.891Z'
---

## Overview

An out-of-bounds read in libXi's XI2 class parsing via size_classes() and copy_classes() in libXi before 1.8.4 could be used by malicous servers to crash the X client.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93542.json)