CVE-2023-6816: A flaw was found in X.Org server. Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for each logical button currently down. Buttons can...

Description

A flaw was found in X.Org server. Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for each logical button currently down. Buttons can be arbitrarily mapped to any value up to 255, but the X.Org Server was only allocating space for the device's particular number of buttons, leading to a heap overflow if a bigger value was used.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

2.11%

79.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
X.Org	X Server	< 21.1.11
X.Org	Xwayland	< 23.2.4
Fedoraproject	Fedora	39
Redhat	Enterprise Linux Desktop	7.0
Redhat	Enterprise Linux Server	7.0
Redhat	Enterprise Linux Workstation	7.0
Debian	Debian Linux	10.0

References

Timeline

Published: Jan 18, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-6816?

A flaw was found in X.Org server. Both DeviceFocusEvent and the XIQueryPointer reply contain a bit for each logical button currently down. Buttons can be arbitrarily mapped to any value up to 255, but the X.Org Server was only allocating space for the device's particular number of buttons, leading to a heap overflow if a bigger value was used.

How severe is CVE-2023-6816?

CVE-2023-6816 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 2.11% probability of exploitation in the next 30 days.

How do I fix CVE-2023-6816?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.