X.Org Server ChangeDrawableAttributes Out-Of-Bounds Read Information Disclosure Vulnerability

June 24th, 2026
ZDI-26-396 ZDI-CAN-30165

CVE ID

CVE-2026-50262

CVSS Score

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

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 the numAttribs field. The issue results from the lack of proper validation of user-supplied data, which can result in a read past the end of an allocated data structure. 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/6d459e4daf715bea8abdafa8fb130be2f8a1d145

Disclosure Timeline

  • 2026-04-17 - Vulnerability reported to vendor
  • 2026-06-24 - Coordinated public release of advisory
  • 2026-06-24 - Advisory Updated

Credit

Anonymous

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