# CVE-2026-98726: nvme-multipath: fix underflow in ANA log bounds checks

> An integer underflow in the Linux kernel NVMe multipath driver allows out-of-bounds reads, potentially causing information disclosure or system crashes.

- **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:** 21 Oct 2026
- **Also known as:** AZL-108617, BELL-CVE-2026-98726, DEBIAN-CVE-2026-98726, GHSA-6fg9-pffg-wphf, UBUNTU-CVE-2026-98726

## What is CVE-2026-98726?

CVE-2026-98726 is a 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:

nvme-multipath: fix underflow in ANA log bounds checks

The number of ANA groups advertised through Identify Controller sizes the
ANA log buffer. The ANA log header and group descriptors independently
supply the number of groups and namespace IDs to parse.

Both bounds checks subtract an untrusted object size from ana_log_size
before comparing the current offset. If the object is larger than the
buffer, the size_t subtraction underflows and lets the parser read beyond
ana_log_buf.

Check the current offset before the first subtraction and compare each
object size with the remaining buffer instead. This rejects inconsistent
ANA data before dereferencing a truncated group descriptor or walking an
oversized namespace ID array.

## Which versions are affected by CVE-2026-98726?


## How do I fix CVE-2026-98726?

Apply the vendor's patch.

## Is CVE-2026-98726 being exploited?

There is no known exploitation of CVE-2026-98726 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98726 and fix it if it is affected.

What it is: CVE-2026-98726 is a 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-2026-98726 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-2026-98726/ (Markdown: https://insights.sbomify.com/CVE-2026-98726/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98726
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98726
- OSV: https://osv.dev/vulnerability/CVE-2026-98726

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98726/
Summaries are generated and may contain mistakes; the official description above is the record.