# CVE-2026-98569: ip_gre: Reject enabling collect metadata through changelink

> A local attacker with high privileges can disrupt network metadata processing for GRE devices by improperly enabling collect metadata mode via changelink.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 18 Oct 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-109091, BELL-CVE-2026-98569, DEBIAN-CVE-2026-98569, GHSA-hr5p-wrg7-45pp, UBUNTU-CVE-2026-98569

## What is CVE-2026-98569?

CVE-2026-98569 is a denial of service vulnerability in Linux, published on 18 Oct 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:

ip_gre: Reject enabling collect metadata through changelink

ipgre_netlink_parms() can enable collect_md on an existing GRE, GRETAP
or ERSPAN device. Unlike newlink, changelink does not enforce metadata
tunnel uniqueness. Converting a non-metadata device can therefore
replace the metadata receive entry for another device of the same type
in the same netns. Deleting either device then clears the shared entry,
breaking metadata receive lookup for the surviving device.

If parameter validation fails after collect_md is set, deleting the
modified device can also clear an entry it never owned.

Reject enabling metadata mode in both changelink callbacks before any
encapsulation or tunnel parameters are modified. Allow requests that
repeat the metadata attribute on an existing metadata device.

## Which versions are affected by CVE-2026-98569?


## How do I fix CVE-2026-98569?

Apply the vendor's patch.

## Is CVE-2026-98569 being exploited?

There is no known exploitation of CVE-2026-98569 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98569 and fix it if it is affected.

What it is: CVE-2026-98569 is a denial of service vulnerability in Linux, published on 18 Oct 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-2026-98569 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-2026-98569/ (Markdown: https://insights.sbomify.com/CVE-2026-98569/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98569
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98569
- OSV: https://osv.dev/vulnerability/CVE-2026-98569

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98569/
Summaries are generated and may contain mistakes; the official description above is the record.