# CVE-2016-3309: Microsoft Windows Kernel Privilege Escalation

> Local attackers can gain elevated privileges on Windows systems by exploiting a vulnerability in kernel-mode drivers via a crafted application.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Yes, since 15 Mar 2022 (CISA KEV), used in ransomware
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 9 Aug 2016
- **Updated:** 21 Oct 2025
- **Also known as:** GHSA-7cmx-3w9q-4v5g

## What is CVE-2016-3309?

CVE-2016-3309 is a high-severity vulnerability in Microsoft Windows 10 1507, published on 9 Aug 2016. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

The kernel-mode drivers in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows Server 2012 Gold and R2; Windows RT 8.1; and Windows 10 Gold, 1511, and 1607 allow local users to gain privileges via a crafted application, aka "Win32k Elevation of Privilege Vulnerability," a different vulnerability than CVE-2016-3308, CVE-2016-3310, and CVE-2016-3311.

## Which versions are affected by CVE-2016-3309?

It affects 9 products.


Products: Microsoft Windows 10 1507, Microsoft Windows 10 1511, Microsoft Windows 10 1607, Microsoft Windows 7, Microsoft Windows 8.1, Microsoft Windows Rt 8.1, Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Vista.

## How do I fix CVE-2016-3309?

No fix has been published for CVE-2016-3309 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 5 Apr 2022.

## Is CVE-2016-3309 being exploited?

Yes. Attackers have exploited CVE-2016-3309 in the wild since at least 15 Mar 2022, including in ransomware campaigns.

Public exploit code:

- Exploits for the win32kfull!bFill vulnerability on Win10 x64 RS2 using Bitmap or Palette techniques (github_poc): https://github.com/siberas/CVE-2016-3309_Reloaded
- Microsoft Windows 10 RS2 (x64) - 'win32kfull!bFill' Pool Overflow (exploitdb)

## Other vulnerabilities in Microsoft Windows 10 1507

- [CVE-2017-8543](https://insights.sbomify.com/CVE-2017-8543/): Microsoft Windows Search Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2025-33053](https://insights.sbomify.com/CVE-2025-33053/): Microsoft Windows External Control of File Name or Path (high 8.8, exploited in the wild)
- [CVE-2025-33073](https://insights.sbomify.com/CVE-2025-33073/): Microsoft Windows SMB Client Improper Access Control (high 8.8, exploited in the wild)
- [CVE-2024-49039](https://insights.sbomify.com/CVE-2024-49039/): Microsoft Windows Task Scheduler Privilege Escalation (high 8.8, exploited in the wild)
- [CVE-2024-43461](https://insights.sbomify.com/CVE-2024-43461/): Microsoft Windows MSHTML Platform Spoofing (high 8.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2016-3309 and fix it if it is affected.

What it is: CVE-2016-3309 is a high-severity vulnerability in Microsoft Windows 10 1507, published on 9 Aug 2016. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: Yes. Attackers have exploited CVE-2016-3309 in the wild since at least 15 Mar 2022, including in ransomware campaigns.

Affected product: Microsoft Windows 10 1507. 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-2016-3309/ (Markdown: https://insights.sbomify.com/CVE-2016-3309/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2016-3309
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2016-3309
- OSV: https://osv.dev/vulnerability/CVE-2016-3309

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From sbomify Insights: https://insights.sbomify.com/CVE-2016-3309/
Summaries are generated and may contain mistakes; the official description above is the record.