# CVE-2026-98057: ring-buffer: Add checking nr_subbufs to persistent ring buffer validation

> A missing validation check in the Linux kernel's persistent ring buffer allows memory corruption, potentially leading to system crashes or arbitrary code execution.

- **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:** 25 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2026-98057, DEBIAN-CVE-2026-98057, GHSA-rx4w-f847-mv59, UBUNTU-CVE-2026-98057

## What is CVE-2026-98057?

CVE-2026-98057 is a memory corruption vulnerability in Linux, published on 25 Sep 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:

ring-buffer: Add checking nr_subbufs to persistent ring buffer validation

Sashiko reported that the code was using meta->nr_subbufs without making
sure that it matched the nr_pages + 1 on data that was assuming the two
were the same.

Add a check to the persistent ring buffer validation code to make sure
that the saved nr_subbufs matches what we expect.

## Which versions are affected by CVE-2026-98057?


## How do I fix CVE-2026-98057?

Apply the vendor's patch.

## Is CVE-2026-98057 being exploited?

There is no known exploitation of CVE-2026-98057 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98057 and fix it if it is affected.

What it is: CVE-2026-98057 is a memory corruption vulnerability in Linux, published on 25 Sep 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-2026-98057 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-2026-98057/ (Markdown: https://insights.sbomify.com/CVE-2026-98057/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98057
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98057
- OSV: https://osv.dev/vulnerability/CVE-2026-98057

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98057/
Summaries are generated and may contain mistakes; the official description above is the record.