# CVE-2026-43094: ixgbevf: add missing negotiate_features op to Hyper-V ops table

> A missing function pointer in the ixgbevf driver causes a kernel crash on Hyper-V VMs during device probe, leading to 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:** 6 May 2026
- **Updated:** 15 Oct 2026
- **Also known as:** BELL-CVE-2026-43094, DEBIAN-CVE-2026-43094, GHSA-8c3v-5v6w-588p, ROOT-OS-DEBIAN-12-CVE-2026-43094, ROOT-OS-UBUNTU-2404-CVE-2026-43094, UBUNTU-CVE-2026-43094

## What is CVE-2026-43094?

CVE-2026-43094 is a medium-severity vulnerability in Linux kernel, published on 6 May 2026. 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:

ixgbevf: add missing negotiate_features op to Hyper-V ops table

Commit a7075f501bd3 ("ixgbevf: fix mailbox API compatibility by
negotiating supported features") added the .negotiate_features callback
to ixgbe_mac_operations and populated it in ixgbevf_mac_ops, but forgot
to add it to ixgbevf_hv_mac_ops. This leaves the function pointer NULL
on Hyper-V VMs.

During probe, ixgbevf_negotiate_api() calls ixgbevf_set_features(),
which unconditionally dereferences hw->mac.ops.negotiate_features().
On Hyper-V this results in a NULL pointer dereference:

  BUG: kernel NULL pointer dereference, address: 0000000000000000
  [...]
  Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine [...]
  Workqueue: events work_for_cpu_fn
  RIP: 0010:0x0
  [...]
  Call Trace:
   ixgbevf_negotiate_api+0x66/0x160 [ixgbevf]
   ixgbevf_sw_init+0xe4/0x1f0 [ixgbevf]
   ixgbevf_probe+0x20f/0x4a0 [ixgbevf]
   local_pci_probe+0x50/0xa0
   work_for_cpu_fn+0x1a/0x30
   [...]

Add ixgbevf_hv_negotiate_features_vf() that returns -EOPNOTSUPP and
wire it into ixgbevf_hv_mac_ops. The caller already handles -EOPNOTSUPP
gracefully.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-43094?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43094?

Apply the vendor's patch.

## Is CVE-2026-43094 being exploited?

There is no known exploitation of CVE-2026-43094 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43094 and fix it if it is affected.

What it is: CVE-2026-43094 is a medium-severity vulnerability in Linux kernel, published on 6 May 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-2026-43094 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2026-43094/ (Markdown: https://insights.sbomify.com/CVE-2026-43094/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43094
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43094
- OSV: https://osv.dev/vulnerability/CVE-2026-43094

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43094/
Summaries are generated and may contain mistakes; the official description above is the record.