Red Hat Security Advisory

RHSA-2026:52398

xorg-x11-server-Xwayland security update

Released 2026-08-10 · Red Hat rating Important · View on Red Hat →

Fixed in

Red Hat Enterprise Linux AppStream E4S (v.9.4) xorg-x11-server-Xwayland-22.1.9-8.el9_4.3

Fixes 2 records

TI-2026-40395 CVE-2026-56000 · GHSA-4gcc-rqqq-58jp

xorg-x11-server / xwayland GLX contextTags Use-After-Free in CommonMakeCurrent()

MEDIUM 41

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent() pointing into potentiall…

CVSS 4.0CRITICAL 9.0 Network Low privileges No interaction EPSS 0.00308 Published 2026-07-08 Partial fix · 21.1.24, 24.1.13 CWE-416

TI-2026-40394 CVE-2026-55999 · GHSA-h655-847g-q4f7

xorg-server / xwayland glamor font atlas Heap Buffer Overflow

LOW 39

Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks.

CVSS 3.1HIGH 8.5 Network Low privileges No interaction EPSS 0.00333 Published 2026-07-08 Fixed in 21.1.24, 24.1.13 CWE-122