Summary
Xwayland is an X server for running X clients under Wayland.
Security Fix(es):
* xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow (CVE-2026-55999)
* X.org: xorg-x11-server: GLX contextTags Use-After-Free in CommonMakeCurrent() (CVE-2026-56000)
For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.
Fixed packages 2
| Release | Package | Fixed in |
|---|---|---|
| AlmaLinux · 9 | xorg-x11-server-Xwayland | 24.1.9-4.el9_8.3 |
| AlmaLinux · 9 | xorg-x11-server-Xwayland-devel | 24.1.9-4.el9_8.3 |
Vulnerabilities 2
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Critical 9.0
xorg-x11-server / xwayland GLX contextTags Use-After-Free in CommonMakeCurrent()
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 potentially reallocated memory.
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High 8.5
xorg-server / xwayland glamor font atlas Heap Buffer Overflow
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.