# CVE-2026-74708: xsk: validate launch-time metadata size

> The Linux kernel XSK subsystem fails to validate metadata size and flags, potentially allowing local attackers to cause memory corruption or privilege escalation.

- **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:** 22 Aug 2026
- **Updated:** 16 Oct 2026
- **Also known as:** BELL-CVE-2026-74708, DEBIAN-CVE-2026-74708, GHSA-qvq6-8jqj-q3p2, UBUNTU-CVE-2026-74708

## What is CVE-2026-74708?

CVE-2026-74708 is a high-severity missing authorization vulnerability in Linux, published on 22 Aug 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: validate launch-time metadata size

Launch-time metadata extends beyond the first 16 bytes of struct
xsk_tx_metadata. Reject the request when the registered metadata area does
not contain the complete field.

Snapshot the validated flags for the generic transmit path and use that
snapshot for request and completion processing, avoiding inconsistent
decisions if user space changes the flags concurrently.

Note that only xsk_skb_metadata is properly using the flags,
__xsk_buff_get_metadata ignores them. Next commits address that.

## Which versions are affected by CVE-2026-74708?


## How do I fix CVE-2026-74708?

Apply the vendor's patch.

## Is CVE-2026-74708 being exploited?

There is no known exploitation of CVE-2026-74708 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74708 and fix it if it is affected.

What it is: CVE-2026-74708 is a high-severity missing authorization vulnerability in Linux, published on 22 Aug 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-2026-74708 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-2026-74708/ (Markdown: https://insights.sbomify.com/CVE-2026-74708/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74708
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74708
- OSV: https://osv.dev/vulnerability/CVE-2026-74708

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74708/
Summaries are generated and may contain mistakes; the official description above is the record.