---
id: CVE-2026-85921
title: >-
  Double free in Windows Secure Kernel Mode allows an authorized attacker to
  elevate privileges locally.
summary: >-
  Double free in Windows Secure Kernel Mode allows an authorized attacker to
  elevate privileges locally.
severity: high
cvss: 8.2
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-415
vendor: microsoft
product: windows_11_26h1
affected:
  - windows_11_26h1 < 10.0.28000.2956
patched:
  - windows_11_26h1 10.0.28000.2956
published: '2026-09-14'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T19:24:48.280'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-85921'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85921'
    label: secure@microsoft.com
tags:
  - nvd
  - cve.org
epss: 0.00348
epssPercentile: 0.28294
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-14T19:11:21.507210Z'
ingestedAt: '2026-09-14T19:13:23.460Z'
---

## Overview

Double free in Windows Secure Kernel Mode allows an authorized attacker to elevate privileges locally.

## Affected

- `windows_11_26h1 < 10.0.28000.2956`

## Remediation

Upgrade past the affected range:

- `windows_11_26h1 10.0.28000.2956`