# CVE-2026-98417: net: xfrm: reject unrepresentable espintcp transport headers

> A remote attacker can cause a denial of service in the Linux kernel by sending crafted ESP-in-TCP packets that trigger a transport header offset warning.

- **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:** 14 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-108126, BELL-CVE-2026-98417, DEBIAN-CVE-2026-98417, GHSA-mmvw-8jc6-xq5j, UBUNTU-CVE-2026-98417

## What is CVE-2026-98417?

CVE-2026-98417 is a denial of service vulnerability in Linux, published on 14 Oct 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: xfrm: reject unrepresentable espintcp transport headers

ESP-in-TCP can hand xfrm packets whose transport header offset no longer
fits after the stream parser trims the TCP envelope. The plain transport
header reset truncates that offset and triggers the skb warning path.

Use the careful transport-header helper and drop the skb through the
existing XFRM error path when the offset cannot be represented.

## Which versions are affected by CVE-2026-98417?


## How do I fix CVE-2026-98417?

Apply the vendor's patch.

## Is CVE-2026-98417 being exploited?

There is no known exploitation of CVE-2026-98417 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98417 and fix it if it is affected.

What it is: CVE-2026-98417 is a denial of service vulnerability in Linux, published on 14 Oct 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-2026-98417 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-2026-98417/ (Markdown: https://insights.sbomify.com/CVE-2026-98417/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98417
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98417
- OSV: https://osv.dev/vulnerability/CVE-2026-98417

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98417/
Summaries are generated and may contain mistakes; the official description above is the record.