# CVE-2026-83634: Windows BitLocker Elevation of Privilege Vulnerability

> An authorized local attacker can exploit a double free in BitLocker to elevate privileges on Windows systems.

- **Severity:** High 7.8 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-fv8x-g67f-8m97

## What is CVE-2026-83634?

CVE-2026-83634 is a high-severity use after free vulnerability in Microsoft Windows 11 23h2, published on 13 Oct 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 BitLocker allows an authorized attacker to elevate privileges locally.

Weakness: CWE-415 (Double Free)

## Which versions are affected by CVE-2026-83634?

It affects 7 products.


Products: Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2, Microsoft Windows 11 26h1, Microsoft Windows 11 26h2, Microsoft Windows Server 2022, Microsoft Windows Server 2025.

## How do I fix CVE-2026-83634?

No fix has been published for CVE-2026-83634 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-83634 being exploited?

There is no known exploitation of CVE-2026-83634 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Windows 11 23h2

- [CVE-2026-81963](https://insights.sbomify.com/CVE-2026-81963/): Microsoft Windows Link Following (high 7.8, exploited in the wild)
- [CVE-2026-100219](https://insights.sbomify.com/CVE-2026-100219/): Microsoft QUIC Remote Code Execution Vulnerability (critical 9.8)
- [CVE-2026-96909](https://insights.sbomify.com/CVE-2026-96909/): Windows BitLocker Remote Code Execution Vulnerability (critical 9.8)
- [CVE-2026-62815](https://insights.sbomify.com/CVE-2026-62815/): Microsoft QUIC Remote Code Execution Vulnerability (critical 9.8)
- [CVE-2026-45657](https://insights.sbomify.com/CVE-2026-45657/): Windows Kernel Remote Code Execution Vulnerability (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-83634 and fix it if it is affected.

What it is: CVE-2026-83634 is a high-severity use after free vulnerability in Microsoft Windows 11 23h2, published on 13 Oct 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-2026-83634 in the wild and no public exploit code.

Affected product: Microsoft Windows 11 23h2. 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-2026-83634/ (Markdown: https://insights.sbomify.com/CVE-2026-83634/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-83634
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-83634
- OSV: https://osv.dev/vulnerability/CVE-2026-83634

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-83634/
Summaries are generated and may contain mistakes; the official description above is the record.