X.Org Server GestureBuildSprite Use-After-Free Information Disclosure Vulnerability

October 16th, 2026
ZDI-26-780 ZDI-CAN-32753

CVE ID

CVE-2026-93536

CVSS Score

4.4 AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L

Affected Vendors

X.Org

Affected Products

Server

Vulnerability Details

This vulnerability allows local attackers to disclose sensitive information on affected installations of X.Org Server. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.

The specific flaw exists within the handling of Window objects. The issue results from the lack of validating the existence of an object prior to performing operations on the object. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of root.

Additional Details

X.Org has issued an update to correct this vulnerability. More details can be found at:
https://gitlab.freedesktop.org/xorg/xserver/-/commit/efcfd8acc754

Disclosure Timeline

  • 2026-09-02 - Vulnerability reported to vendor
  • 2026-10-16 - Coordinated public release of advisory
  • 2026-10-16 - Advisory Updated

Credit

4nibhal

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