Red Hat Security Advisory

RHSA-2026:53450

xorg-x11-server-Xwayland security update

Released 2026-08-11 · Red Hat rating Important · View on Red Hat →

Fixed in

Red Hat Enterprise Linux AppStream AUS (v.8.6) xorg-x11-server-Xwayland-21.1.3-2.el8_6.8
Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) xorg-x11-server-Xwayland-21.1.3-2.el8_6.8

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