CVE-2026-94285: Out-of-bounds read in libX11's byte-oriented codeset parser

Severity: medium (CVSS 5.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-28 · updated 2026-09-30
Weakness: CWE-125

Description

An out-of-bounds read in libX11's byte-oriented codeset parser in libX11 before 1.8.14 could be used by malicious X servers to crash attached X clients.

Affected products

x.org libX11: before 1.8.14 — fixed in 1.8.14

How to fix

Upgrade to a fixed version: x.org libX11 1.8.14. Check the vendor advisory for mitigations.

References

https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/310/diffs?commit_id=980868483446f24f9658d26aa5bfa42f3da6dd3a

Get alerted when CVE-2026-94285 or the next vulnerability affects your stack