# CVE-2026-80875: ipvs: use parsed transport offset in TCP state lookup

> An attacker can cause memory corruption or denial of service in the Linux kernel IPVS module by sending crafted IPv6 packets with extension headers.

- **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:** 4 Sep 2026
- **Updated:** 4 Sep 2026
- **Also known as:** BELL-CVE-2026-80875, DEBIAN-CVE-2026-80875, GHSA-x476-x69x-m4jr, UBUNTU-CVE-2026-80875

## What is CVE-2026-80875?

CVE-2026-80875 is a memory corruption vulnerability in Linux, published on 4 Sep 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:

ipvs: use parsed transport offset in TCP state lookup

TCP state handling reparses the skb to find the TCP header. For IPv6 it
uses sizeof(struct ipv6hdr), while the surrounding IPVS code already
parsed the packet with ip_vs_fill_iph_skb() and has the real
transport-header offset in iph.len.

This makes TCP state handling look at the wrong bytes when an IPv6
packet carries extension headers. Use the parsed transport offset passed
down from ip_vs_set_state() when reading the TCP header.

For IPv4 and for IPv6 packets without extension headers, the passed
offset matches the previous value.

## Which versions are affected by CVE-2026-80875?


## How do I fix CVE-2026-80875?

Apply the vendor's patch.

## Is CVE-2026-80875 being exploited?

There is no known exploitation of CVE-2026-80875 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-80875 and fix it if it is affected.

What it is: CVE-2026-80875 is a memory corruption vulnerability in Linux, published on 4 Sep 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-2026-80875 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-2026-80875/ (Markdown: https://insights.sbomify.com/CVE-2026-80875/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-80875
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-80875
- OSV: https://osv.dev/vulnerability/CVE-2026-80875

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-80875/
Summaries are generated and may contain mistakes; the official description above is the record.