X.Org Server XKB SetMap Key Width/Action Count Desync Out-Of-Bounds Read

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-93524
StatePUBLISHED
Assignersuse
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-28 17:18:53 UTC
Updated2026-11-06 19:18:02 UTC
DescriptionA buffer overread in CheckKeySyms() in X.Org X Server before 21.1.25 and XWayland before 24.1.14 could be used by authenticated X clients to leak small amounts of information from X server memory or potentially crash the X server.

Risk And Classification

Primary CVSS: v4.0 6.9 MEDIUM from [email protected]

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.001770000 probability, percentile 0.072900000 (date 2026-11-08)

Problem Types: CWE-126 | CWE-126 CWE-126 Buffer over-read

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary6.9MEDIUMCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS6.9MEDIUMCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
None
Confidentiality
Low
Integrity
None
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA X.org Xorg-x11-server affected 21.1.25 rpm Not specified
CNA X.org Xwayland affected 24.1.14 rpm Not specified

References

ReferenceSourceLinkTags
gitlab.freedesktop.org/xorg/xserver/-/commit/cea71d0273e4d5092aa9c6a8a770734c8935c02e [email protected] gitlab.freedesktop.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: WONJOON HWANG (@joon1337) working with TrendAI Zero Day Initiative (en)

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