CVE-2026-34003 | Xorg: xwayland: x.org x server: information exposure and denial of service via out-of-bounds memory access

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.

Published: 2026-04-23 Last update: 2026-06-02 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-34003 is rated Low Risk (31.8/100): CVSS High severity, with low exploitation likelihood (EPSS 0.01%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-34003

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-24 0.01%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-34003

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 5.9 [email protected]

Weakness enumeration for CVE-2026-34003

GitHub Security Advisory for CVE-2026-34003

GHSA-5mqr-3465-c7p6 · Severity: high — A flaw was found in the X.Org X server's XKB key types request validation. A local attacker could...

OS Trackers for CVE-2026-34003

vendor priority summary link
debian not yet assigned CVE-2026-34003 not yet assigned priority: Debian including 2 source packages (xorg-server, xwayland), 9 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6, open 3. https://security-tracker.debian.org/tracker/CVE-2026-34003
redhat high https://access.redhat.com/security/cve/CVE-2026-34003
suse medium https://www.suse.com/security/cve/CVE-2026-34003/
ubuntu medium CVE-2026-34003 medium priority: Ubuntu including 7 source packages (xorg, xorg-hwe-16.04, …), 46 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 16, needs-triage 16, not-affected 12, released 2. https://ubuntu.com/security/CVE-2026-34003

Affected software / configurations for CVE-2026-34003

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-34003

URL Tags
https://access.redhat.com/errata/RHSA-2026:10739
https://access.redhat.com/errata/RHSA-2026:11352
https://access.redhat.com/errata/RHSA-2026:11369
https://access.redhat.com/errata/RHSA-2026:11388
https://access.redhat.com/errata/RHSA-2026:11656
https://access.redhat.com/errata/RHSA-2026:11692
https://access.redhat.com/errata/RHSA-2026:13414
https://access.redhat.com/errata/RHSA-2026:19125
https://access.redhat.com/errata/RHSA-2026:19342
https://access.redhat.com/errata/RHSA-2026:19343
https://access.redhat.com/errata/RHSA-2026:19344
https://access.redhat.com/errata/RHSA-2026:20547
https://access.redhat.com/errata/RHSA-2026:20555
https://access.redhat.com/errata/RHSA-2026:20557
https://access.redhat.com/errata/RHSA-2026:20558
https://access.redhat.com/errata/RHSA-2026:20560
https://access.redhat.com/errata/RHSA-2026:20561
https://access.redhat.com/errata/RHSA-2026:20562
https://access.redhat.com/errata/RHSA-2026:20563
https://access.redhat.com/errata/RHSA-2026:20575
https://access.redhat.com/errata/RHSA-2026:20576
https://access.redhat.com/errata/RHSA-2026:20590
https://access.redhat.com/errata/RHSA-2026:21699
https://access.redhat.com/errata/RHSA-2026:21712
https://access.redhat.com/errata/RHSA-2026:21715
https://access.redhat.com/errata/RHSA-2026:21716
https://access.redhat.com/errata/RHSA-2026:21718
https://access.redhat.com/errata/RHSA-2026:21741
https://access.redhat.com/errata/RHSA-2026:21742
https://access.redhat.com/errata/RHSA-2026:22424
https://access.redhat.com/errata/RHSA-2026:22456
https://access.redhat.com/security/cve/CVE-2026-34003
https://bugzilla.redhat.com/show_bug.cgi?id=2451113
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