NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. In versions prior to 0.24, Syscall 15 (MemoryMapRange) allows Ring 3 user-mode processes to map arbitrary virtual address ranges into their address space without validating against forbidden regions, including critical kernel structures such as the IDT, GDT, TSS, and page tables. A local attacker can exploit this to modify kernel interrupt handlers, resulting in privilege escalation from user mode to kernel context. This issue has been fixed in version 0.24.