# CVE-2026-74559: xsk: drain continuation descs after overflow in xsk_build_skb()

> A flaw in the Linux kernel's AF_XDP transmit path causes descriptor loss on overflow, leading to potential denial of service.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 15 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-96483, BELL-CVE-2026-74559, DEBIAN-CVE-2026-74559, GHSA-9hgr-2c8j-c3h6, UBUNTU-CVE-2026-74559

## What is CVE-2026-74559?

CVE-2026-74559 is a denial of service vulnerability in Linux, published on 15 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: drain continuation descs after overflow in xsk_build_skb()

Fix generic xmit path multi-buffer logic when packets are either too big
(count of descriptors exceed MAX_SKB_FRAGS) or an invalid descriptor is
included in fragmented packet. Introduce xdp_sock::drain_cont and act
upon this flag - when it is set, keep on consuming descriptors from
AF_XDP Tx ring and put them directly onto Cq. Previously these
descriptors were silently lost and could never be reached again.

## Which versions are affected by CVE-2026-74559?


## How do I fix CVE-2026-74559?

Apply the vendor's patch.

## Is CVE-2026-74559 being exploited?

There is no known exploitation of CVE-2026-74559 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74559 and fix it if it is affected.

What it is: CVE-2026-74559 is a denial of service vulnerability in Linux, published on 15 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-2026-74559 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-2026-74559/ (Markdown: https://insights.sbomify.com/CVE-2026-74559/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74559
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74559
- OSV: https://osv.dev/vulnerability/CVE-2026-74559

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74559/
Summaries are generated and may contain mistakes; the official description above is the record.