CVE intelligence

CVE-2026-34003

Vulnerability intelligence

Published Apr 23, 2026Sources checked Nov 11, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-34003 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Sep 25, 2026

CBL-Mariner Releases Release Notes

Vendor-listed releases

24.1.6-4

CISA KEVNot listedBased on the latest collected catalog

EPSS0.3%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-34003?

A flaw was found in the X.Org X server's XKB key types request validation. A local attacker could send a specially crafted request to the X server, leading to an out-of-bounds memory access vulnerability.

This could result in the disclosure of sensitive information or cause the server to crash, leading to a Denial of Service (DoS). In certain configurations, higher impact outcomes may be possible.

Source: NVD