# CVE-2026-72017: net: macb: drop in-flight Tx SKBs on close

> A memory leak in the Linux kernel MACB network driver can lead to resource exhaustion and denial of service when network interfaces are closed.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 23 Aug 2026
- **Also known as:** BELL-CVE-2026-72017, DEBIAN-CVE-2026-72017, GHSA-v3cw-v56w-xqgw, UBUNTU-CVE-2026-72017

## What is CVE-2026-72017?

CVE-2026-72017 is a memory corruption vulnerability in Linux, published on 15 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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

net: macb: drop in-flight Tx SKBs on close

The MACB driver has since forever leaked the outgoing SKBs that
have not yet been marked as completed. They live in queue->tx_skb
which gets freed without remorse nor checking.

macb_free_consistent() gets called in a few codepaths, but only close will
trigger the added expressions. In macb_open() and macb_alloc_consistent()
failure cases, queues' tx_skb just got allocated and are empty.

## Which versions are affected by CVE-2026-72017?


## How do I fix CVE-2026-72017?

Apply the vendor's patch.

## Is CVE-2026-72017 being exploited?

There is no known exploitation of CVE-2026-72017 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72017 and fix it if it is affected.

What it is: CVE-2026-72017 is a memory corruption vulnerability in Linux, published on 15 Aug 2026. 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-2026-72017 in the wild and no public exploit code.

Affected product: 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-2026-72017/ (Markdown: https://insights.sbomify.com/CVE-2026-72017/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72017
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72017
- OSV: https://osv.dev/vulnerability/CVE-2026-72017

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72017/
Summaries are generated and may contain mistakes; the official description above is the record.