Red Hat - Red Hat Enterprise Linux 10 - CRITICAL - CVE-2026-4408. A significant flaw exists in Samba, particularly affecting file servers and classic domain controllers that utilize the 'check password script' feature. When configured with the %u substitution character, this vulnerability allows remote attackers to execute commands by exploiting improper handling of user input. The exploit is most potent in non-standard configurations where this feature is active, leading to the possibility of remote command execution through the samba-dcerpcd service, potentially compromising system integrity.