# CVE-2026-64228: net: ethtool: phy: avoid NULL deref when PHY driver is unbound

> A local attacker can cause a kernel crash by unbinding a PHY driver while it is still attached, leading to a null pointer dereference in the ethtool subsystem.

- **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:** 24 Jul 2026
- **Updated:** 24 Jul 2026
- **Also known as:** BELL-CVE-2026-64228, DEBIAN-CVE-2026-64228, GHSA-wx96-hrff-2rc8, ROOT-OS-UBUNTU-2204-CVE-2026-64228, UBUNTU-CVE-2026-64228

## What is CVE-2026-64228?

CVE-2026-64228 is a medium-severity vulnerability in Linux kernel, published on 24 Jul 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:

net: ethtool: phy: avoid NULL deref when PHY driver is unbound

phydev->drv can become NULL while the phy_device is still attached to
its net_device, namely after the PHY driver is unbound via sysfs:

	echo <mdio_id> > /sys/bus/mdio_bus/drivers/<phy_drv>/unbind

phy_remove() clears phydev->drv but doesn't call phy_detach(), so the
phy_device stays in the link topology xarray and ethnl_req_get_phydev()
still hands it back. ETHTOOL_MSG_PHY_GET then oopses on:

	rep_data->drvname = kstrdup(phydev->drv->name, GFP_KERNEL);

drvname is already treated as optional by phy_reply_size(),
phy_fill_reply() and phy_cleanup_data(), so just skip the allocation
when there is no driver bound.

Weakness: CWE-476 (NULL Pointer Dereference)

## Which versions are affected by CVE-2026-64228?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64228?

Apply the vendor's patch.

## Is CVE-2026-64228 being exploited?

There is no known exploitation of CVE-2026-64228 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-2026-64228 and fix it if it is affected.

What it is: CVE-2026-64228 is a medium-severity vulnerability in Linux kernel, published on 24 Jul 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-2026-64228 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-2026-64228/ (Markdown: https://insights.sbomify.com/CVE-2026-64228/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64228
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64228
- OSV: https://osv.dev/vulnerability/CVE-2026-64228

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64228/
Summaries are generated and may contain mistakes; the official description above is the record.