CVE-2026-93524: X.Org Server XKB SetMap Key Width/Action Count Desync Out-Of-Bounds Read

Q: Which systems are affected?

X.Org X Server versions before 21.1.25 and XWayland versions before 24.1.14 are affected.

Q: What access does an attacker need?

An attacker must be able to act as an authenticated X client. The issue is not described as exploitable by an unauthenticated remote party.

Q: What could exploitation cause?

A malicious authenticated X client could leak small amounts of X server memory or potentially crash the X server.

Published Oct 28, 2026

Updated

A 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.

Affected Software

2 affected components

X.Org X.Org X Server<21.1.25

X.Org Xwayland<24.1.14

Event History

Oct 28, 2026

CVE Published

via MITRE·04:24 PM

Data Sourced

via MITRE·04:24 PM

DescriptionWeakness

Frequently Asked Questions

Which systems are affected?

X.Org X Server versions before 21.1.25 and XWayland versions before 24.1.14 are affected.

What access does an attacker need?

An attacker must be able to act as an authenticated X client. The issue is not described as exploitable by an unauthenticated remote party.

What could exploitation cause?

A malicious authenticated X client could leak small amounts of X server memory or potentially crash the X server.

CVE-2026-93524: X.Org Server XKB SetMap Key Width/Action Count Desync Out-Of-Bounds Read

Affected Software

Event History

Frequently Asked Questions

Which systems are affected?

What access does an attacker need?

What could exploitation cause?

Company

Resources

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Frequently Asked Questions

Which systems are affected?

What access does an attacker need?

What could exploitation cause?