{"id":"CVE-2026-40573","kind":"vulnerability","aliases":["CVE-2026-40573"],"related":[],"title":"NovumOS: malicious Nova script gives local user kernel privileges","description":"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.","summary":"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.","severity":"high","cvss":8.6,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["hobby-os","novumos","other","zig"],"not_affected_if":["fixed-version","not-novumos"],"how_to_check":"- Check the NovumOS version in use; affected versions are those before `0.25-beta.1`.\n- Look for the Nova interpreter in `zig/nova/vm.zig` in your source tree.","fix":"- Move to `0.25-beta.1` or later.","status":"open","published_at":"2026-10-30T21:16:53+00:00","first_seen_at":"2026-10-30T21:25:52+00:00","triaged_at":"2026-10-30T21:26:31+00:00","updated_at":"2026-10-30T21:26:31+00:00","category":"other","confidence":0.7,"triage":{"at":"2026-10-30T21:26:31Z","model":"claude-haiku-5-5","output":{"fix":"- Move to `0.25-beta.1` or later.","reach":"local","title":"NovumOS: malicious Nova script gives local user kernel privileges","impact":"high","summary":"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.","audience":"businesses","category":"other","nicknames":[],"who_cares":["novumos","zig","hobby-os"],"confidence":0.7,"fix_status":"available","needs_auth":"yes","worst_case":"local user gains kernel privileges and runs arbitrary code","analyst_note":"","how_to_check":"- Check the NovumOS version in use; affected versions are those before `0.25-beta.1`.\n- Look for the Nova interpreter in `zig/nova/vm.zig` in your source tree.","plain_action":"","needs_analyst":false,"not_affected_if":["not-novumos","fixed-version"],"who_is_affected":"Only systems running NovumOS before 0.25-beta.1 that let users load .nv scripts through the shell are exposed. Anyone not running NovumOS can skip this entry.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000659,"input_tokens":4210,"output_tokens":476,"severity_before":"high"},"analyst_status":null,"analyst_note":null,"search":"'-2026':11A,14A '-40573':12A,15A '0':88C '0.25':35B,80C,145C '3':136C '32':26B,67C 'access':94C 'advisori':117C 'affect':125C 'assembl':76C 'beta.1':36B,81C,146C 'bit':27B,68C 'check':115C 'code':59B,109C 'compon':126C 'custom':66C 'cve':10A,13A 'domain':138C 'execut':108C,128C 'fix':142C 'give':5A 'hobbi':17B,25B 'hobby-o':16B 'identifi':118C 'initi':120C 'interpret':40B,84C 'isol':131C 'issu':140C 'kernel':8A,43B,61B,92C,111C 'kernel-memori':91C 'let':54B 'load':50B,95C 'local':6A,56B,105C 'malici':2A,47B,97C 'memori':93C 'mode':44B 'nova':3A,38B,83C 'novumo':1A,19B,22B,63C 'nv':48B,98C 'oper':28B,69C 'os':18B 'permit':103C 'prior':77C 'privileg':9A,62B,112C,137C 'restrict':134C 'ring':87C,135C 'run':41B,58B,85C 'script':4A,39B,49B,99C,127C 'secur':114C 'shell':53B,102C 'system':29B,70C 'unrestrict':90C 'user':7A,57B,106C 'version':34B,79C,144C 'vm':119C 'without':113C 'written':30B,71C 'x86':75C 'zig':21B,32B,73C 'zig/nova/vm.zig':122C","nicknames":[],"mitigations":[],"who_affected":"Only systems running NovumOS before 0.25-beta.1 that let users load .nv scripts through the shell are exposed. Anyone not running NovumOS can skip this entry.","tier":"B","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"businesses","plain_action":null,"first_public_at":"2026-10-30T21:16:53+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-40573","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-40573","severity":null,"published_at":"2026-10-30T21:16:53+00:00","modified_at":"2026-10-30T21:16:53+00:00","first_seen_at":"2026-10-30T21:25:52+00:00","fetched_at":"2026-10-30T21:25:52+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}