# CVE-2026-40317: NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. In versions prior to 0.24, Syscall 12…

Source: https://junglewise.ai/threats/cve-2026-40317-novumos-is-a-custom-32-bit-operating-system-written-in-zig-and  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-18  
License: CC BY 4.0 with a link back

CVE-2026-40317 · Severity: critical · CVSS 9.3 · Published 2026-04-18

NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. In versions prior to 0.24, Syscall 12 (JumpToUser) accepts an arbitrary entry point address from user-space registers without validation, allowing any Ring 3 user-mode process to jump to kernel addresses and execute arbitrary code in Ring 0 context, resulting in local privilege escalation. This issue has been fixed in version 0.24. If developers are unable to immediately update, they should restrict syscall access by running the system in single-user mode without Ring 3, and disable user-mode processes by only running kernel shell with no user processes. This issue has been fixed in version 0.24.

Technologies: [Minecanton209 Novumos](https://junglewise.ai/threats/technologies/novumos). Vendors: [Minecanton209](https://junglewise.ai/threats/vendors/minecanton209).

## Quick answers

**Is CVE-2026-40317 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-40317 being exploited in the wild.

**How severe is CVE-2026-40317?** Critical severity, with a CVSS score of 9.3, published 18 April 2026.

**Which products and versions are affected?** Minecanton209 Novumos. The advisory does not name versions.

**Is there a fix for CVE-2026-40317?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2026-40317?** Check whether you run Minecanton209 Novumos. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Minecanton209 Novumos

## Related threats

- [NovumOS Nova interpreter privilege escalation](https://junglewise.ai/threats/cve-2026-40573-novumos-is-a-custom-32-bit-operating-system-written-in-zig-and)
- [NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. In versions prior to 0.24, Syscall 15…](https://junglewise.ai/threats/cve-2026-40572-novumos-is-a-custom-32-bit-operating-system-written-in-zig-and)