setuid() does not drop all privileges due to io_uring

Summary

setuid() does not affect libuv's internal io_uring operations if initialized before the call to setuid(). This allows the process to perform privileged operations despite presumably having dropped such privileges through a call to setuid().

This vulnerability affects all users using version greater or equal than Node.js 18.18.0, Node.js 20.4.0 and Node.js 21.