# CVE-2026-43093: xsk: tighten UMEM headroom validation to account for tailroom and min frame

> Insufficient headroom validation in Linux kernel XSK UMEM allows memory corruption, potentially leading to code execution or denial of service.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-43093, DEBIAN-CVE-2026-43093, GHSA-m2xh-q35x-h5f5, ROOT-OS-DEBIAN-11-CVE-2026-43093, ROOT-OS-DEBIAN-12-CVE-2026-43093, ROOT-OS-UBUNTU-2204-CVE-2026-43093, ROOT-OS-UBUNTU-2404-CVE-2026-43093, UBUNTU-CVE-2026-43093

## What is CVE-2026-43093?

CVE-2026-43093 is a high-severity memory corruption 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:

xsk: tighten UMEM headroom validation to account for tailroom and min frame

The current headroom validation in xdp_umem_reg() could leave us with
insufficient space dedicated to even receive minimum-sized ethernet
frame. Furthermore if multi-buffer would come to play then
skb_shared_info stored at the end of XSK frame would be corrupted.

HW typically works with 128-aligned sizes so let us provide this value
as bare minimum.

Multi-buffer setting is known later in the configuration process so
besides accounting for 128 bytes, let us also take care of tailroom space
upfront.

Weakness: CWE-787 (Out-of-bounds Write)

## Which versions are affected by CVE-2026-43093?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-43093?

Apply the vendor's patch.

## Is CVE-2026-43093 being exploited?

There is no known exploitation of CVE-2026-43093 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-2026-43093 and fix it if it is affected.

What it is: CVE-2026-43093 is a high-severity memory corruption 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-2026-43093 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-2026-43093/ (Markdown: https://insights.sbomify.com/CVE-2026-43093/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43093
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43093
- OSV: https://osv.dev/vulnerability/CVE-2026-43093

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43093/
Summaries are generated and may contain mistakes; the official description above is the record.