# CVE-2020-0909: Windows Hyper-V Denial of Service Vulnerability

> An attacker can cause a denial of service on Windows Hyper-V by sending specially crafted network packets, requiring a security patch.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 May 2020
- **Updated:** 19 Aug 2026
- **Also known as:** GHSA-29r6-grc2-5h75

## What is CVE-2020-0909?

CVE-2020-0909 is a high-severity denial of service vulnerability in Microsoft Windows 10, published on 21 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A denial of service vulnerability exists when Hyper-V on a Windows Server fails to properly handle specially crafted network packets.
To exploit the vulnerability, an attacker would send specially crafted network packets to the Hyper-V Server.
The security update addresses the vulnerability by resolving the conditions where Hyper-V would fail to properly handle these network packets.

## Which versions are affected by CVE-2020-0909?

It affects 7 products.


Products: Microsoft Windows 10, Microsoft Windows 7, Microsoft Windows 8.1, Microsoft Windows Server 2008, Microsoft Windows Server 2012, Microsoft Windows Server 2016, Microsoft Windows Server 2019.

## How do I fix CVE-2020-0909?

No fix has been published for CVE-2020-0909 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-0909 being exploited?

There is no known exploitation of CVE-2020-0909 in the wild and no public exploit code.

## Other vulnerabilities in Microsoft Windows 10

- [CVE-2015-2426](https://insights.sbomify.com/CVE-2015-2426/): Microsoft Windows Adobe Type Manager Library Remote Code Execution (high 8.8, exploited in the wild)
- [CVE-2015-1769](https://insights.sbomify.com/CVE-2015-1769/): Microsoft Windows Mount Manager Privilege Escalation (medium 6.6, exploited in the wild)
- [CVE-2020-1467](https://insights.sbomify.com/CVE-2020-1467/): Windows Hard Link Elevation of Privilege Vulnerability (critical 10.0)
- [CVE-2021-26424](https://insights.sbomify.com/CVE-2021-26424/): Windows TCP/IP Remote Code Execution Vulnerability (critical 9.9)
- [CVE-2021-28476](https://insights.sbomify.com/CVE-2021-28476/): Windows Hyper-V Remote Code Execution Vulnerability (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-0909 and fix it if it is affected.

What it is: CVE-2020-0909 is a high-severity denial of service vulnerability in Microsoft Windows 10, published on 21 May 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-0909 in the wild and no public exploit code.

Affected product: Microsoft Windows 10. 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-2020-0909/ (Markdown: https://insights.sbomify.com/CVE-2020-0909/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-0909
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-0909
- OSV: https://osv.dev/vulnerability/CVE-2020-0909

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-0909/
Summaries are generated and may contain mistakes; the official description above is the record.