# CVE-2026-85921: Windows Secure Kernel Mode Elevation of Privilege Vulnerability

> An authorized local attacker can exploit a double free in Windows Secure Kernel Mode to elevate privileges.

- **Severity:** High 8.2 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 14 Oct 2026
- **Also known as:** GHSA-2q4x-w73p-vjf4

## What is CVE-2026-85921?

CVE-2026-85921 is a high-severity use after free vulnerability in Microsoft Windows 11 26h1, published on 14 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

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

Weakness: CWE-415 (Double Free)

## Which versions are affected by CVE-2026-85921?

It affects 1 product.


Products: Microsoft Windows 11 26h1.

## How do I fix CVE-2026-85921?

No fix has been published for CVE-2026-85921 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-85921 being exploited?

There is no known exploitation of CVE-2026-85921 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Windows 11 26h1

- [CVE-2026-83939](https://insights.sbomify.com/CVE-2026-83939/): Windows Secure Kernel Mode Elevation of Privilege Vulnerability (high 8.2)
- [CVE-2026-105005](https://insights.sbomify.com/CVE-2026-105005/): Windows Schannel Remote Code Execution Vulnerability (high 8.1)
- [CVE-2026-85850](https://insights.sbomify.com/CVE-2026-85850/): Windows Kernel Elevation of Privilege Vulnerability (high 7.8)
- [CVE-2026-97803](https://insights.sbomify.com/CVE-2026-97803/): Windows Kernel Elevation of Privilege Vulnerability (high 7.8)
- [CVE-2026-69544](https://insights.sbomify.com/CVE-2026-69544/): Windows SMB Client Elevation of Privilege Vulnerability (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-85921 and fix it if it is affected.

What it is: CVE-2026-85921 is a high-severity use after free vulnerability in Microsoft Windows 11 26h1, published on 14 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-85921 in the wild and no public exploit code.

Affected product: Microsoft Windows 11 26h1. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-85921/ (Markdown: https://insights.sbomify.com/CVE-2026-85921/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-85921
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-85921
- OSV: https://osv.dev/vulnerability/CVE-2026-85921

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-85921/
Summaries are generated and may contain mistakes; the official description above is the record.