---
id: "CVE-2026-40573"
kind: "vulnerability"
aliases: ["CVE-2026-40573"]
title: "NovumOS: malicious Nova script gives local user kernel privileges"
severity: "high"
cvss: 8.6
epss: null
exploited: false
status: "open"
category: "other"
products: []
ecosystems: []
tags: ["hobby-os", "novumos", "other", "zig"]
not_affected_if: ["fixed-version", "not-novumos"]
published_at: "2026-10-30T21:16:53+00:00"
first_seen_at: "2026-10-30T21:25:52+00:00"
updated_at: "2026-10-30T21:26:31+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40573", "first_seen_at": "2026-10-30T21:25:52+00:00"}]
---

# NovumOS: malicious Nova script gives local user kernel privileges

NovumOS is a hobby 32-bit operating system written in Zig. Before version 0.25-beta.1, its Nova script interpreter runs in kernel mode, so a malicious .nv script loaded through the shell lets a local user run code with kernel privileges.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the NovumOS version in use; affected versions are those before `0.25-beta.1`.
- Look for the Nova interpreter in `zig/nova/vm.zig` in your source tree.

## Fix

- Move to `0.25-beta.1` or later.

## Timeline

- 2026-10-30T21:25:52+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-40573

## From the sources

NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. Prior to version 0.25-beta.1, the `Nova` interpreter runs in Ring 0 with unrestricted kernel-memory access. Loading a malicious `.nv` script through the shell permits a local user to execute code with kernel privileges without security checks. The advisory identifies VM initialization in `zig/nova/vm.zig` as the affected component; script execution is not isolated in a restricted Ring 3 privilege domain. This issue is fixed in version 0.25-beta.1.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_