# CVE-2026-97548: xfs: fix the rtrmap and rtrefcount _maxlevels_ondisk functions

> A flaw in the Linux kernel XFS filesystem allows out-of-bounds memory access, potentially leading to system crashes or arbitrary code execution.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 25 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-97548, DEBIAN-CVE-2026-97548, GHSA-w932-ggqv-vxgq, UBUNTU-CVE-2026-97548

## What is CVE-2026-97548?

CVE-2026-97548 is a high-severity memory corruption vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

xfs: fix the rtrmap and rtrefcount _maxlevels_ondisk functions

The _maxlevels_ondisk functions are used to compute the size of
in-memory btree cursors for each btree type.  Unfortunately, LOLLM
noticed that the rtrmap and rtrefcount versions of these functions
forget to account for the inode root, which means that we could access
beyond the end of the cursor given a sufficiently large btree.  Fix
this.

## Which versions are affected by CVE-2026-97548?


## How do I fix CVE-2026-97548?

Apply the vendor's patch.

## Is CVE-2026-97548 being exploited?

There is no known exploitation of CVE-2026-97548 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97548 and fix it if it is affected.

What it is: CVE-2026-97548 is a high-severity memory corruption vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-97548 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-2026-97548/ (Markdown: https://insights.sbomify.com/CVE-2026-97548/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97548
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97548
- OSV: https://osv.dev/vulnerability/CVE-2026-97548

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97548/
Summaries are generated and may contain mistakes; the official description above is the record.