# CVE-2026-98872: freevxfs: don't BUG() on unknown typed-extent type


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 26 Oct 2026
- **Also known as:** AZL-110593, BELL-CVE-2026-98872, DEBIAN-CVE-2026-98872, GHSA-35fj-5v77-5rpx, UBUNTU-CVE-2026-98872

## What is CVE-2026-98872?

CVE-2026-98872 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

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

freevxfs: don't BUG() on unknown typed-extent type

vxfs_bmap_typed() handles four typed-extent types and calls BUG() in
its default case, so an on-disk typed extent with any other type value
crashes the kernel. It is reachable from ioctl(FIBMAP) on a regular
file:

  kernel BUG at fs/freevxfs/vxfs_bmap.c:230!
  RIP: vxfs_bmap_typed fs/freevxfs/vxfs_bmap.c:230 [inline]
       vxfs_bmap1+0x128a/0x12d0 fs/freevxfs/vxfs_bmap.c:257

Replace the BUG() with WARN_ON_ONCE() and return 0 -- the value
vxfs_bmap_typed() already returns on failure (and from the DEV4 case
above); vxfs_getblk() maps 0 to -EIO, so the ioctl fails cleanly.

## Which versions are affected by CVE-2026-98872?


## How do I fix CVE-2026-98872?

Upgrade to a fixed version.

## Is CVE-2026-98872 being exploited?

There is no known exploitation of CVE-2026-98872 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98872 and fix it if it is affected.

What it is: CVE-2026-98872 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98872 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-2026-98872/ (Markdown: https://insights.sbomify.com/CVE-2026-98872/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98872
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98872
- OSV: https://osv.dev/vulnerability/CVE-2026-98872

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98872/
Summaries are generated and may contain mistakes; the official description above is the record.