# CVE-2026-93536: X.Org X Server use after free in gesture sprite lifecycle

Source: https://junglewise.ai/threats/cve-2026-93536-a-use-after-free-caused-by-missing-lifecycle-management-of  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-28. Updated: 2026-10-28  
License: CC BY 4.0 with a link back

CVE-2026-93536 · Severity: medium · CVSS 5.3 · Published 2026-10-28

X.Org X Server is the display system that manages graphics on Linux desktops and servers. An authenticated X client can crash the X server or potentially execute code by exploiting missing cleanup of gesture sprite traces when windows are destroyed. This could allow an attacker with local access to disrupt the graphical environment or gain system privileges.

Technologies: [X.Org X Server](https://junglewise.ai/threats/technologies/x-org-x-server), [X.Org XWayland](https://junglewise.ai/threats/technologies/x-org-xwayland). Vendors: [X.Org](https://junglewise.ai/threats/vendors/x-org).

## Quick answers

**Is CVE-2026-93536 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-93536 being exploited in the wild.

**How severe is CVE-2026-93536?** Medium severity, with a CVSS score of 5.3, published 28 October 2026.

**Which products and versions are affected?** X.Org X Server before 21.1.25; X.Org XWayland before 24.1.14.

**Is there a fix for CVE-2026-93536?** Yes: fixed in X Server 21.1.25, XWayland 24.1.14. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-93536 attacked?** It is attacked with local access, in a hosted service.

**Am I affected by CVE-2026-93536?** Check whether you run X.Org X Server or X.Org XWayland at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in X Server 21.1.25, XWayland 24.1.14

## Technical details

A use-after-free in GestureBuildSprite() occurs when gesture sprite traces containing unrefcounted window pointers are not cleaned up during window destruction, leaving dangling pointers. If a device supports gestures but lacks a TouchClass, the cleanup logic skips gesture sprite cleanup, and DeliverOneGestureEvent() later dereferences the stale pointer via DeepestSpriteWin(&gi->sprite)->drawable.id. The vulnerability requires an authenticated X client to trigger window destruction during an active gesture.

## Affected products

- X.Org X Server before 21.1.25
- X.Org XWayland before 24.1.14

## Timeline

- 2026-10-28: disclosed: CVE-2026-93536 published
- 2026-09-03: patched: Fix committed (efcfd8ac) by Peter Hutterer

## References

- [https://gitlab.freedesktop.org/xorg/xserver/-/commit/efcfd8acc754c5ac4b2555ff375dd5101d735b0a](https://gitlab.freedesktop.org/xorg/xserver/-/commit/efcfd8acc754c5ac4b2555ff375dd5101d735b0a)

## Related threats

- [X.Org X Server buffer overread in CheckKeySyms](https://junglewise.ai/threats/cve-2026-93524-a-buffer-overread-in-checkkeysyms-in-x-org-x-server-before-21-1)
- [X.Org X Server heap buffer overflow in XIPassiveUngrabDevice](https://junglewise.ai/threats/cve-2026-93523-a-heap-buffer-overflow-caused-by-a-xipassiveungrabdevice-request)
- [X.Org X Server heap buffer overflow in CopyArea CPU-to-FBO](https://junglewise.ai/threats/cve-2026-93522-a-heap-buffer-overflow-caused-by-mismatched-size-usage-in)
- [X.Org X Server buffer overflow in RandR ChangeProviderProperty](https://junglewise.ai/threats/cve-2026-93521-a-buffer-overflow-in-randr-changeproviderproperty-requests-in-x)
- [X.org X server heap buffer overflow in XkbAllocNames](https://junglewise.ai/threats/cve-2026-93520-a-heap-buffer-overflow-caused-by-mismatching-size-calculations)