# CVE-2026-93683: Dpdk: dpdk: guest-triggered out-of-bounds walk via vhost indirect descriptor length toctou

> A guest can trigger a race condition in the DPDK vhost library to cause an out-of-bounds memory walk, crashing the host vhost process.

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:L/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Oct 2026
- **Updated:** 14 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-93683, GHSA-vg6x-f7m9-xx3h, UBUNTU-CVE-2026-93683

## What is CVE-2026-93683?

CVE-2026-93683 is a medium-severity vulnerability in Red Hat Fast Datapath for RHEL 10, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A flaw was found in the DPDK vhost library. When handling a virtio indirect descriptor table, the host reads the table length more than once from guest memory and can allocate a host copy before validating that length. A guest that changes the length between those reads, or that supplies an out-of-range next index on a small host copy in the vDPA relay path, can cause the host vhost process to walk past the validated mapping or heap copy. That can crash or disrupt the vhost process. Out-of-bounds bytes are consumed as descriptor fields for GPA translation and are not returned to the guest as payload. This is a residual issue in the non-contiguous indirect descriptor copy path introduced as part of the CVE-2018-1059 fix.

Weakness: CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition)

## Which versions are affected by CVE-2026-93683?


## How do I fix CVE-2026-93683?

Apply the vendor's patch.

## Is CVE-2026-93683 being exploited?

There is no known exploitation of CVE-2026-93683 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-93683 and fix it if it is affected.

What it is: CVE-2026-93683 is a medium-severity vulnerability in Red Hat Fast Datapath for RHEL 10, published on 14 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-2026-93683 in the wild and no public exploit code.

Affected product: Red Hat Fast Datapath for RHEL 10. 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-2026-93683/ (Markdown: https://insights.sbomify.com/CVE-2026-93683/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-93683
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-93683
- OSV: https://osv.dev/vulnerability/CVE-2026-93683

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-93683/
Summaries are generated and may contain mistakes; the official description above is the record.