A flaw was found in the X.Org X server. This integer underflow vulnerability, specifically in the XKB compatibility map handling, allows an attacker with local or remote X11 server access to trigger a buffer read overrun. This can lead to memory-safety violations and potentially a denial of service (DoS) or other severe impacts.
To mitigate this issue, restrict access to the X11 server. For remote access, disable X11 forwarding in SSH configurations if not required. Edit /etc/ssh/sshd_config and set X11Forwarding no. After modifying the configuration, restart the sshd service using systemctl restart sshd. Disabling X11 forwarding may impact remote graphical applications.