# CVE-2026-42980 — Microsoft Windows 10 Version 1607

> As of 2026-07-23, CVE-2026-42980 is a HIGH-severity vulnerability in Microsoft Windows 10 Version 1607, CVSS v3.1 7.8, EPSS 6.9% (93.4th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-42980, most recently “CVE-2026-42980: Windows NT OS Kernel Local Privilege Escalation via WMI Integer Underflow (Public PoC)”.

**Last updated:** 2026-07-23

## What is CVE-2026-42980?

Integer underflow (wrap or wraparound) in Windows NT OS Kernel allows an authorized attacker to elevate privileges locally.

The record classifies CVE-2026-42980 under weakness classes [CWE-191](https://cwe.mitre.org/data/definitions/191.html), [CWE-122](https://cwe.mitre.org/data/definitions/122.html). Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 12 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 113 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.8 — HIGH (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **EPSS (FIRST):** 6.9% probability of exploitation in the next 30 days, higher than 93.4% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 9.6/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-06-09, last modified 2026-07-23

## Is CVE-2026-42980 being exploited?

Weaponised exploit code for CVE-2026-42980 is publicly available. 1 public proof-of-concept repository is tracked for this identifier.

- [G4sp4rCS/CVE-2026-42980-POC](https://github.com/G4sp4rCS/CVE-2026-42980-POC) (github)

## Affected products and versions

- **Microsoft**: Windows 10 Version 1607, Windows 10 Version 1809, Windows 10 Version 21H2, Windows 10 Version 22H2, Windows 11 version 23H2, Windows 11 Version 23H2, Windows 11 Version 24H2, Windows 11 Version 25H2, Windows 11 version 26H1, Windows Server 2012, Windows Server 2012 (Server Core installation), Windows Server 2012 R2

## How to fix CVE-2026-42980

Vendor advisory: [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42980](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42980). Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory.

## Threat activity tracking CVE-2026-42980

1 tracked threat in the Threadlinqs corpus references CVE-2026-42980, either in the campaign’s CVE list or as an indicator on the campaign record.

- [CVE-2026-42980: Windows NT OS Kernel Local Privilege Escalation via WMI Integer Underflow (Public PoC)](https://intel.threadlinqs.com/threat/TL-2026-1707) — HIGH · 2026-07-26

## Sources

Enriched from CVE.org, NVD, FIRST EPSS, GitHub Security Advisories, public proof-of-concept repositories. Last verified by Threadlinqs on 2026-07-26. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [msrc.microsoft.com — vendor advisory](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42980)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-42980
Full detection coverage and IOCs for threats exploiting CVE-2026-42980 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp