# CVE-2026-64410: netfilter: flowtable: IPIP tunnel hardware offload is not yet support

> The Linux kernel fails to properly handle unsupported IPIP tunnel hardware offload, potentially causing resource exhaustion or instability when such configurations are attempted.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:** 25 Jul 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-64410, GHSA-grq9-9wcr-7jrj, ROOT-OS-UBUNTU-2204-CVE-2026-64410, UBUNTU-CVE-2026-64410

## What is CVE-2026-64410?

CVE-2026-64410 is a critical denial of service vulnerability in Linux kernel, published on 25 Jul 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:

netfilter: flowtable: IPIP tunnel hardware offload is not yet support

No driver supports for IPIP tunnels yet, give up early on setting up the
hardware offload for this scenario.

This patch adds a stub that can be enhanced to add more configuration
that are currently not supported. As of now, the offload work is
enqueued to the worker, then ignored if the hardware offload
configuration is not supported.

Check the NF_FLOW_HW flag to know if this entry was already tried once
to be offloaded so this is not retried on refresh when unsupported. Move
NF_FLOW_HW flag check to nf_flow_offload_add(). If this NF_FLOW_HW flag
is unset the _del and _stats variants are never called.

This can be updated later on to skip hardware offload work to be queued
in case hardware offload does not support it.

## Which versions are affected by CVE-2026-64410?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-64410?

Apply the vendor's patch.

## Is CVE-2026-64410 being exploited?

There is no known exploitation of CVE-2026-64410 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-2026-64410 and fix it if it is affected.

What it is: CVE-2026-64410 is a critical denial of service vulnerability in Linux kernel, published on 25 Jul 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-2026-64410 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-2026-64410/ (Markdown: https://insights.sbomify.com/CVE-2026-64410/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-64410
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-64410
- OSV: https://osv.dev/vulnerability/CVE-2026-64410

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-64410/
Summaries are generated and may contain mistakes; the official description above is the record.