What is CVE-2026-94284?

CVE-2026-94284 is a medium-severity vulnerability in X.org Libx11, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2026-09-28.

How severe is CVE-2026-94284?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Out-of-bounds Read in X.org Libx11

CVE-2026-94284

An out-of-bounds read vulnerability in libX11's XIM trigger-key registration parser in libX11 before 1.8.14 could be used by malicious X servers to crash attached X clients.

Vulnerability class: Buffer Overflow

Published 2026-09-28.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.001 (0.9th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 0.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

X.org Libx11

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/310/diffs (patch)

Frequently asked questions

What is CVE-2026-94284?: CVE-2026-94284 is a medium-severity vulnerability in X.org Libx11, classified under Out-of-bounds Read. CVSS score: 5.5/10. Published 2026-09-28.
How severe is CVE-2026-94284?: Medium severity. CVSS v3 base score is 5.5 out of 10.