# CVE-2026-74373: md/raid1,raid10: fix bio accounting for split md cloned bios

> A bug in Linux kernel RAID1/10 bio accounting causes incorrect statistics, potentially leading to resource management issues or denial of service.

- **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:** 15 Aug 2026
- **Updated:** 21 Oct 2026
- **Also known as:** AZL-96323, BELL-CVE-2026-74373, DEBIAN-CVE-2026-74373, GHSA-w5h2-43j2-4p8f, UBUNTU-CVE-2026-74373

## What is CVE-2026-74373?

CVE-2026-74373 is a vulnerability in Linux, published on 15 Aug 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:

md/raid1,raid10: fix bio accounting for split md cloned bios

Use md_cloned_bio() to control bio accounting instead of relying
on r1bio_existed in raid1 or the io_accounting flag in raid10.

The previous logic does not reliably reflect whether a bio is an
md cloned bio. When a failed bio is split and resubmitted via
bio_submit_split_bioset() on the error path, this can lead to either
double accounting for md cloned bios, or missing accounting for bios
returned from bio_submit_split_bioset()

Fix this by using md_cloned_bio() to detect md cloned bios and
skip accounting accordingly.

## Which versions are affected by CVE-2026-74373?


## How do I fix CVE-2026-74373?

Apply the vendor's patch.

## Is CVE-2026-74373 being exploited?

There is no known exploitation of CVE-2026-74373 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74373 and fix it if it is affected.

What it is: CVE-2026-74373 is a vulnerability in Linux, published on 15 Aug 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-2026-74373 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-2026-74373/ (Markdown: https://insights.sbomify.com/CVE-2026-74373/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74373
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74373
- OSV: https://osv.dev/vulnerability/CVE-2026-74373

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74373/
Summaries are generated and may contain mistakes; the official description above is the record.