An out-of-bounds read vulnerability in libX11's XIM (X Input Method) attribute parser in libX11 before 1.8.14 could be used by malicious X servers… (CVE-2026-94283)
Description
An out-of-bounds read vulnerability exists in libX11's X Input Method (XIM) attribute parser in versions before 1.8.14. This flaw could be exploited by a malicious X server to crash connected X clients, causing a denial of service. The vulnerability has a medium severity rating with a CVSS score of 6.5. Fixes are available in updated libx11 package versions across multiple Ubuntu releases.
CVSS v3.1
Score 6.5medium
Affected software
pkg:deb/ubuntu/libx11?arch=source&distro=esm-infra-legacy/trustypkg:deb/ubuntu/libx11?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/libx11?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/libx11?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/libx11?arch=source&distro=jammypkg:deb/ubuntu/libx11?arch=source&distro=noblepkg:deb/ubuntu/libx11?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-94283 describes an out-of-bounds read vulnerability in the XIM attribute parser component of libX11 prior to version 1.8.14. This vulnerability allows a malicious X server to send crafted XIM messages that cause libX11 clients to crash. The issue results in denial of service but no confirmed code execution. The vulnerability affects numerous Ubuntu package versions of libx11, and patches have been released to address the issue.
Potential Impact
If exploited, a malicious X server can cause libX11 clients to crash, resulting in denial of service. There is no confirmed impact on confidentiality or integrity, and no known exploits in the wild. The vulnerability requires the client to connect to a malicious X server, which may limit exposure.
Mitigation Recommendations
A fix is available and has been released by Ubuntu in updated libx11 package versions for all supported releases including 14.04 LTS through 26.04 LTS. Users should apply the security updates and reboot their systems to ensure the vulnerability is remediated. Ubuntu Pro users have access to extended support and fixes. No additional mitigation is required beyond applying the official patches.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-94283
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:26.04:LTS"]
- Cvss Version
- 3.1
- State
- PUBLISHED
Patch Information
Threat ID: 6acd555a2cdf04f656da85df
Added to database: 10/12/2026, 21:47:06 UTC
Last enriched: 10/12/2026, 22:00:45 UTC
Last updated: 10/12/2026, 22:00:45 UTC
Views: 2
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