Multiple security vulnerabilities have been identified in X.Org X server and Xwayland prior to versions 21.1.23 and 24.1.12 respectively. These include stack-based buffer overflows in font alias resolution and XKB key type handling, as well as several use-after-free vulnerabilities in XSYNC components. The vulnerabilities could allow local attackers with limited privileges to cause memory corruption leading to potential code execution or denial of service. Fixes have been released in xorg-server-21.1.23 and xwayland-24.1.12.