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.
CVE-2023-6816
CVSS base score
9.8 (v3.1)
Severity
CRITICAL
Attack vector
Network
Weakness
CWE-787
Last modified
November 4, 2026
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
x.org x server
x.org xwayland
fedoraproject fedora
redhat enterprise linux desktop
redhat enterprise linux server
redhat enterprise linux workstation
debian debian linux