RHEL 9 must disable the use of user namespaces. GROUP ID: V-257816 RULE ID: SV-257816r1014825 User namespaces are used primarily for Linux containers. The value "0" disallows the use of user namespaces.
Solution
Configure RHEL 9 to disable the use of user namespaces by adding the following line to a file, in the "/etc/sysctl.d" directory: user.max_user_namespaces = 0 The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system