X.Org Server ProcDRI2GetBuffers Heap-based Buffer Overflow Privilege Escalation Vulnerability

November 10th, 2026
ZDI-26-901 ZDI-CAN-30557

CVE ID

CVE-2026-50264

CVSS Score

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

Affected Vendors

X.Org

Affected Products

Server

Vulnerability Details

This vulnerability allows local attackers to escalate privileges 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 do_get_buffers function. The issue results from the lack of proper validation of the length of user-supplied data prior to copying it to a heap-based buffer. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root.

Additional Details

https://gitlab.freedesktop.org/xorg/xserver/-/commit/339c279514326134b0878fc23ce6e9520440ce7f, https://gitlab.freedesktop.org/xorg/xserver/-/commit/b7aa65cc3bb11b792ce2a3f511ba9b863acb11c8


Disclosure Timeline

  • 2026-05-29 - Vulnerability reported to vendor
  • 2026-11-10 - Coordinated public release of advisory
  • 2026-11-10 - Advisory Updated

Credit

Anonymous

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