# CVE-2026-23459: ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS

> A memory corruption issue in the Linux kernel's IP tunnel handling can cause system freezes or corruption on 32-bit kernels.

- **Severity:** High 8.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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:** 3 Apr 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-103419, BELL-CVE-2026-23459, DEBIAN-CVE-2026-23459, GHSA-gv4g-88q2-j2qq, UBUNTU-CVE-2026-23459

## What is CVE-2026-23459?

CVE-2026-23459 is a high-severity memory corruption vulnerability in Linux kernel, published on 3 Apr 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:

ip_tunnel: adapt iptunnel_xmit_stats() to NETDEV_PCPU_STAT_DSTATS

Blamed commits forgot that vxlan/geneve use udp_tunnel[6]_xmit_skb() which
call iptunnel_xmit_stats().

iptunnel_xmit_stats() was assuming tunnels were only using
NETDEV_PCPU_STAT_TSTATS.

@syncp offset in pcpu_sw_netstats and pcpu_dstats is different.

32bit kernels would either have corruptions or freezes if the syncp
sequence was overwritten.

This patch also moves pcpu_stat_type closer to dev->{t,d}stats to avoid
a potential cache line miss since iptunnel_xmit_stats() needs to read it.

## Which versions are affected by CVE-2026-23459?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2026-23459?

Apply the vendor's patch.

## Is CVE-2026-23459 being exploited?

There is no known exploitation of CVE-2026-23459 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-2026-23459 and fix it if it is affected.

What it is: CVE-2026-23459 is a high-severity memory corruption vulnerability in Linux kernel, published on 3 Apr 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-2026-23459 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-2026-23459/ (Markdown: https://insights.sbomify.com/CVE-2026-23459/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23459
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23459
- OSV: https://osv.dev/vulnerability/CVE-2026-23459

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-23459/
Summaries are generated and may contain mistakes; the official description above is the record.