The X Window System is a graphical windowing system based on a client/server model.
It was discovered that X.Org X Server did not sufficiently check the length of the XInput extension’s ChangeFeedbackControl request.
An authorized attacker could possibly escalate privileges, or cause a Denial of Service condition.
There is no known workaround at this time.
All X.Org X Server users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=x11-base/xorg-server-1.20.11"