# CVE-2026-74703: vhost-scsi: Validate T10 PI scatterlist counts

> A malformed vhost-scsi request with invalid T10 PI protection bytes can trigger a kernel BUG_ON, causing a denial of service.

- **Severity:** High 7.1 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H`)
- **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:** 22 Aug 2026
- **Updated:** 25 Aug 2026
- **Also known as:** BELL-CVE-2026-74703, DEBIAN-CVE-2026-74703, GHSA-j7pf-235f-jcqv, UBUNTU-CVE-2026-74703

## What is CVE-2026-74703?

CVE-2026-74703 is a high-severity denial of service vulnerability in Linux, published on 22 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:

vhost-scsi: Validate T10 PI scatterlist counts

When T10 PI is negotiated, vhost-scsi splits protection bytes from
the data iterator before mapping the request scatterlists. A malformed
request can claim protection bytes that cover or exceed the full payload
length. The former leaves no data bytes to map, while the latter
underflows exp_data_len before advancing the iterator. Both cases can let
a zero data SGL count reach sg_alloc_table_chained(), which triggers
BUG_ON(!nents).

Reject protection lengths that cover or exceed the payload before
subtracting prot_bytes and advancing the iterator. Also propagate
negative errors from the protection SGL calculation before calling the
allocator, matching the data SGL path.

## Which versions are affected by CVE-2026-74703?


## How do I fix CVE-2026-74703?

Apply the vendor's patch.

## Is CVE-2026-74703 being exploited?

There is no known exploitation of CVE-2026-74703 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-74703 and fix it if it is affected.

What it is: CVE-2026-74703 is a high-severity denial of service vulnerability in Linux, published on 22 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-2026-74703 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-2026-74703/ (Markdown: https://insights.sbomify.com/CVE-2026-74703/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-74703
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-74703
- OSV: https://osv.dev/vulnerability/CVE-2026-74703

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-74703/
Summaries are generated and may contain mistakes; the official description above is the record.