Red Hat Security Advisory

RHSA-2026:50117

xorg-x11-server security update

Released 2026-08-04 · Red Hat rating Important · View on Red Hat →

Fixed in

Red Hat Enterprise Linux Server (v. 7 ELS) xorg-x11-server-1.20.4-36.el7_9, xorg-x11-server-Xephyr-1.20.4-36.el7_9, xorg-x11-server-Xorg-1.20.4-36.el7_9 +1
Red Hat Enterprise Linux Server Optional (v. 7 ELS) xorg-x11-server-Xdmx-1.20.4-36.el7_9, xorg-x11-server-Xnest-1.20.4-36.el7_9, xorg-x11-server-Xvfb-1.20.4-36.el7_9 +4

Fixes 1 record

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