# CVE-2026-98447: xfs: fix wild memcpy access when formatting ondisk rtrefcount btree roots

> A memory corruption vulnerability in the Linux kernel XFS filesystem allows attackers to cause denial of service or execute arbitrary code via wild memcpy access.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **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:** BELL-CVE-2026-98447, DEBIAN-CVE-2026-98447, GHSA-wj43-8f87-c9v3, UBUNTU-CVE-2026-98447

## What is CVE-2026-98447?

CVE-2026-98447 is a memory corruption 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:

xfs: fix wild memcpy access when formatting ondisk rtrefcount btree roots

LOLLM noticed that the inode btree root formatting methods copy too many
bytes -- there's only one set of keys in node blocks, not two.  This
causes memory corruption of whatever's beyond the buffers.

## Which versions are affected by CVE-2026-98447?


## How do I fix CVE-2026-98447?

Apply the vendor's patch.

## Is CVE-2026-98447 being exploited?

There is no known exploitation of CVE-2026-98447 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98447 and fix it if it is affected.

What it is: CVE-2026-98447 is a memory corruption 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-2026-98447 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-2026-98447/ (Markdown: https://insights.sbomify.com/CVE-2026-98447/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98447
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98447
- OSV: https://osv.dev/vulnerability/CVE-2026-98447

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98447/
Summaries are generated and may contain mistakes; the official description above is the record.