I second Franio.
These bug descriptions are all about things "a malicious X server" could do. Are you going to be using "a malicious X server"? Probably not. If using Wayland is an option for you then definately not because it doesn't allow you to run a separate display server, eg. on another computer to the one running the client/application, anyway.
In practice there's rarely ever going to be a reason to trust the X server or client (program that's running, possibly using these libraries) any differently anyway, since they'll both have come from the distro's package repo. So if a malicious X server in installed which can hack into the program you're using, it's just as likely that the program you're using is malicious and will just be naughty on its own.
But anyway Xorg is hardly the only software with lots security alerts, check out
all the vulnerabilities Firefox reports.
Switch to Wayland yourself if you want to. But as an argument for others to do so, these security bugs are irrelevent. I for one value the extra capabilities and software-compatibility of X and will definitely be sticking with it. Tiny Core's TinyX servers are also very resource efficient already.