RHSA-2026:98581: Important: xorg-x11-server-Xwayland security update
Xwayland is an X server for running X clients under Wayland.Security Fix(es): xorg-x11-server: xorg-x11-server: Arbitrary code execution via use-after-free in passive grab handling (CVE-2026-93516) xorg-x11-server: xorg-x11-server: Privilege escalation via crafted RandR provider property requests (CVE-2026-93521) xorg-x11-server: xwayland: xorg-x11-server: Arbitrary code execution via double-free in XKB geometry handling (CVE-2026-88812) xorg-x11-server: xorg-x11-server: Out-of-bounds write via unvalidated modifier in ProcXIPassiveUngrabDevice (CVE-2026-93523) xorg-x11-server: glamor: size tmpbits buffer for source coordinate range in uploadboxes (CVE-2026-93522) xorg-x11-server: xorg-x11-server: arbitrary code execution via GLX RenderLarge heap-based buffer overflow (CVE-2026-93517) xorg-x11-server: xorg-x11-server: arbitrary code execution via integer truncation during keyboard mapping resize (CVE-2026-93518) xorg-x11-server: xorg-x11-server: Arbitrary code execution via buffer overflow in inputconstraincursor() (CVE-2026-93519) xorg-x11-server: xorg-x11-server: arbitrary code execution via out-of-bounds write in XKB keycode handling (CVE-2026-93520) 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.
Affected Software
Event History
Frequently Asked Questions
Which issues in this update could lead to arbitrary code execution?
The advisory identifies arbitrary code execution risks in passive grab handling (CVE-2026-93516), XKB geometry handling in Xwayland (CVE-2026-88812), GLX RenderLarge processing (CVE-2026-93517), keyboard mapping resize handling (CVE-2026-93518), input_constrain_cursor() (CVE-2026-93519), and XKB keycode handling (CVE-2026-93520).
Does the update address privilege escalation as well as code execution?
Yes. CVE-2026-93521 is described as a privilege-escalation issue involving crafted RandR provider property requests.
Are all of the fixes specific to Xwayland?
No. The advisory includes issues in xorg-x11-server generally, one issue explicitly identified in Xwayland, and a glamor issue involving sizing the tmp_bits buffer for source coordinate range handling in upload_boxes.