ZDI 2026-10-15

ZDI-26-768: X.Org Server XInput ProcXIPassiveUngrabDevice Heap-based Buffer Overflow Privilege Escalation Vulnerability

CVE-2026-93523

Machine-generated analysis · WAYSCloud LLM

Heap-based buffer overflow in X.Org Server’s XInput ProcXIPassiveUngrabDevice function enables local privilege escalation.

Context

The advisory affects the X.Org Server XInput component, specifically the ProcXIPassiveUngrabDevice function. It describes a heap-based buffer overflow that can be leveraged for privilege escalation. Exploitation requires the attacker to already execute low-privileged code on the target.

Operator considerations

Check: Verify the installed X.Org Server version and whether it includes the vulnerable ProcXIPassiveUngrabDevice function.
Isolate: Limit execution of untrusted low-privileged code on systems running the affected X.Org Server.

From Zero Day Initiative ↗

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 ZDI has assigned a CVSS rating of 7.8. The following CVEs are assigned: CVE-2026-93523.

Read the full advisory on ZDI →