CVE-2026-40317

CVE-2026-40317 is a critical privilege escalation vulnerability in NovumOS versions prior to 0.24, where Syscall 12 (JumpToUser) fails to validate entry point addresses provided by user-space processes, permitting arbitrary jumps to kernel memory and code execution in Ring 0 context. This flaw affects the custom 32-bit operating system written in Zig and x86 Assembly, enabling any unprivileged Ring 3 user-mode process to achieve immediate local privilege escalation. The vulnerability presents a critical severity profile with a CVSS score of 9.3, characterized by a local attack vector requiring no user interaction or special privileges to exploit. The attack complexity is low, and successful exploitation results in complete system compromise with high impact across confidentiality, integrity, and availability. The vulnerability affects system scope, allowing an attacker to move laterally and compromise the entire system from a single user-mode process. There is currently no evidence of active exploitation, with the KEV catalog marking this as inactive and the EPSS score of 0.0002 indicating low empirical probability of exploitation in the wild. No public exploit code appears to be readily available in community resources. Organizations running affected versions should prioritize immediate patching to version 0.24; interim mitigation requires restricting syscall access by disabling Ring 3 user-mode processes and operating the system in single-user kernel mode only.