Fedora is looking at disallowing X.Org/XWayland clients of difference CPU endianess from connecting to the X.Org Server. Such a combination of different endianess between the X.Org Server and clients is rather rare these days but is yet another “large attack surface” of the X.Org Server that needs addressing…
Source: Phoronix – Fedora Linux Looks To Close Another “Large Attack Surface” With The X.Org Server