CVE-2026-104117: Missing authorization in illumos ipmgmtd allows local users to change persistent IPMP group membership

A missing authorization check in the illumos IP management daemon (ipmgmtd) allows a local user to change the persistent IP multipathing (IPMP) configuration. The ipmgmtd door dispatch table in usr/src/cmd/cmd-inet/lib/ipmgmtd/ipmgmtdoor.c does not require the solaris.network.interface.config authorization for the IPMGMTCMDIPMPUPDATE command, although its handler, ipmgmtipmpupdatehandler(), writes to the persistent ipadm configuration when the IPMGMTPERSIST flag is set. An unprivileged local user can therefore add interfaces to, or remove them from, existing IPMP groups in the stored configuration. The running configuration is not changed; the modification takes effect when the stored configuration is next applied, such as at boot, and may disrupt network connectivity. The flaw has existed since 2021 (illumos-gate commit a73be61a), and affects any illumos distribution prior to illumos-gate commit e8d3efa1.