# CVE-2024-26820: hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed

> A race condition in the Linux kernel's hv_netvsc driver can prevent virtual function registration, potentially causing network denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **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:** Yes
- **Published:** 17 Apr 2024
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2024-26820, DEBIAN-CVE-2024-26820, GHSA-2vvj-hm96-cr7r, UBUNTU-CVE-2024-26820

## What is CVE-2024-26820?

CVE-2024-26820 is a medium-severity vulnerability in Debian Debian Linux, published on 17 Apr 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

hv_netvsc: Register VF in netvsc_probe if NET_DEVICE_REGISTER missed

If hv_netvsc driver is unloaded and reloaded, the NET_DEVICE_REGISTER
handler cannot perform VF register successfully as the register call
is received before netvsc_probe is finished. This is because we
register register_netdevice_notifier() very early( even before
vmbus_driver_register()).
To fix this, we try to register each such matching VF( if it is visible
as a netdevice) at the end of netvsc_probe.

## Which versions are affected by CVE-2024-26820?

It affects 2 products.


Products: Debian Debian Linux, Linux kernel.

## How do I fix CVE-2024-26820?

Apply the vendor's patch.

## Is CVE-2024-26820 being exploited?

There is no known exploitation of CVE-2024-26820 in the wild and no public exploit code.

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- [CVE-2026-24061](https://insights.sbomify.com/CVE-2026-24061/): GNU InetUtils Argument Injection (critical 9.8, exploited in the wild)
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- [CVE-2024-9680](https://insights.sbomify.com/CVE-2024-9680/): Mozilla Firefox Use-After-Free (critical 9.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-26820 and fix it if it is affected.

What it is: CVE-2024-26820 is a medium-severity vulnerability in Debian Debian Linux, published on 17 Apr 2024. 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-2024-26820 in the wild and no public exploit code.

Affected product: Debian Debian Linux. 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-2024-26820/ (Markdown: https://insights.sbomify.com/CVE-2024-26820/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-26820
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-26820
- OSV: https://osv.dev/vulnerability/CVE-2024-26820

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-26820/
Summaries are generated and may contain mistakes; the official description above is the record.