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Response snapshot Oct 27, 2026, 01:26 UTC

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VulnerabilityCVE-2026-40317

NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly.

NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. In versions prior to 0.

At a glance

Exploited
Not known
Severity
9.3 Critical (CVSS 3.1)
Chance of exploitation
Not estimated
Sources
2 independent sources

What to do

Check the vendor advisory for affected versions and fixes.

Read NVD CVE-2026-40317 (opens a new tab)

What happened

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.

Scores and how they were measured

CVSS base severity

9.3

Version 3.1As of

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Measurement source (opens a new tab)

How bad it is if exploited. Not a prediction of exploitation or proof you are exposed.

EPSS probability

Not available

A model's estimate of exploitation in the next 30 days, not certainty or your own risk.

Related technology

Sources

  1. Primary source

    NVD CVE-2026-40317 (opens a new tab)

    NVD record: description, CVSS (the CNA score is preferred), affected products, and publication date. Not evidence of exploitation.

    Published Checked

  2. Primary source

    Vendor advisory (via NVD references) (opens a new tab)

    The vendor advisory referenced by the CVE record, for affected versions and fixes.

    Published Date not suppliedChecked

  3. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

  4. Primary source

    NVD CVE API 2.0 (opens a new tab)

    The NVD API page that supplied this CVE record.

    Published Date not suppliedChecked

Cite this record

For factual claims, cite the primary sources above; cite KEVWire for its compilation, dates, and classifications.

APA

KEVWire. (2026, October 26). NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. (CVE-2026-40317). https://kevwire.com/record/CVE-2026-40317

MLA

"NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. (CVE-2026-40317)." KEVWire, 26 Oct. 2026, kevwire.com/record/CVE-2026-40317.

Chicago

KEVWire. "NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. (CVE-2026-40317)." Last modified October 26, 2026. https://kevwire.com/record/CVE-2026-40317.

Evidence summary (plain text)

NovumOS is a custom 32-bit operating system written in Zig and x86 Assembly. (Apr 18, 2026).
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.
CVSS 9.3 (version 3.1; evidence as of Oct 26, 2026; https://nvd.nist.gov/vuln/detail/CVE-2026-40317).
Sources:
NVD CVE-2026-40317: https://nvd.nist.gov/vuln/detail/CVE-2026-40317
Vendor advisory (via NVD references): https://github.com/MinecAnton209/NovumOS/security/advisories/GHSA-xjx3-gjh9-45fm
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T20:37:18.143Z&lastModEndDate=2026-10-26T22:10:56.995Z&resultsPerPage=500&startIndex=1000
NVD CVE API 2.0: https://services.nvd.nist.gov/rest/json/cves/2.0?lastModStartDate=2026-10-26T20:05:59.720Z&lastModEndDate=2026-10-26T21:35:56.549Z&resultsPerPage=500&startIndex=500
Record ID: CVE-2026-40317.
Record origin: Ingested record.
AI evidence: Not assessed.
Known exploitation: Not assessed.
Zero-day status: Not assessed. KEV membership alone does not establish zero-day status.
About this data

This record was ingested from a data source. Retrieved: Oct 26, 2026, 22:10 UTC. Ingestion is not an independent editorial investigation.

NVD status: Analyzed. Publication in the NVD is not evidence of exploitation.

A CISA KEV listing documents known exploitation, not necessarily a zero-day; absence from the catalog does not prove a vulnerability has never been exploited.

Technology tags indicate possible relevance, not verified exposure. Confirm the affected product, version, and configuration against your own inventory; KEVWire does not scan your systems.

A personal reading checklist on this device, not verified remediation.

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Record details

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