# CVE-2026-43031: net: xilinx: axienet: Fix BQL accounting for multi-BD TX packets

> A bug in the Xilinx AXI Ethernet driver causes TX queue stalls when packets span multiple descriptors, leading to denial of service.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 May 2026
- **Updated:** 5 Aug 2026
- **Also known as:** BELL-CVE-2026-43031, DEBIAN-CVE-2026-43031, GHSA-xpr9-pcwr-h574, UBUNTU-CVE-2026-43031

## What is CVE-2026-43031?

CVE-2026-43031 is a high-severity denial of service vulnerability in Linux kernel, published on 1 May 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: xilinx: axienet: Fix BQL accounting for multi-BD TX packets

When a TX packet spans multiple buffer descriptors (scatter-gather),
axienet_free_tx_chain sums the per-BD actual length from descriptor
status into a caller-provided accumulator. That sum is reset on each
NAPI poll. If the BDs for a single packet complete across different
polls, the earlier bytes are lost and never credited to BQL. This
causes BQL to think bytes are permanently in-flight, eventually
stalling the TX queue.

The SKB pointer is stored only on the last BD of a packet. When that
BD completes, use skb->len for the byte count instead of summing
per-BD status lengths. This matches netdev_sent_queue(), which debits
skb->len, and naturally survives across polls because no partial
packet contributes to the accumulator.

## Which versions are affected by CVE-2026-43031?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43031?

Apply the vendor's patch.

## Is CVE-2026-43031 being exploited?

There is no known exploitation of CVE-2026-43031 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-2026-43031 and fix it if it is affected.

What it is: CVE-2026-43031 is a high-severity denial of service vulnerability in Linux kernel, published on 1 May 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-2026-43031 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-2026-43031/ (Markdown: https://insights.sbomify.com/CVE-2026-43031/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43031
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43031
- OSV: https://osv.dev/vulnerability/CVE-2026-43031

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43031/
Summaries are generated and may contain mistakes; the official description above is the record.