CVE-2026-94283 Out-of-bounds read vulnerability in libX11's XIM (X Input Method) attribute parser
A malicious X server can crash X clients via an out-of-bounds read in libX11's XIM attribute parser, requiring an upgrade to libX11.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-94283?
CVE-2026-94283 is a medium-severity denial of service vulnerability in x.org libX11, published on 28 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
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 to crash attached X clients.
Weakness: CWE-125
Which versions are affected by CVE-2026-94283?
How do I fix CVE-2026-94283?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-94283 being exploited?
There is no known exploitation of CVE-2026-94283 in the wild and no public exploit code.
Sources
Also known as ALPINE-CVE-2026-94283, AZL-104963, BELL-CVE-2026-94283, DEBIAN-CVE-2026-94283, ECHO-4c1a-f6d4-292c, GHSA-j5qx-6vm4-vfcj and 1 more.