# CVE-2023-46842: x86 HVM hypercalls may trigger Xen bug check

> A malicious HVM guest can crash the Xen hypervisor by triggering a consistency check failure during hypercall continuation processing.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/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:** 16 May 2024
- **Updated:** 4 Nov 2025
- **Also known as:** ALPINE-CVE-2023-46842, DEBIAN-CVE-2023-46842, GHSA-hcr5-hp8w-36q9, UBUNTU-CVE-2023-46842

## What is CVE-2023-46842?

CVE-2023-46842 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 16 May 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and
other modes.  This in particular means that they may set registers used
to pass 32-bit-mode hypercall arguments to values outside of the range
32-bit code would be able to set them to.

When processing of hypercalls takes a considerable amount of time,
the hypervisor may choose to invoke a hypercall continuation.  Doing so
involves putting (perhaps updated) hypercall arguments in respective
registers.  For guests not running in 64-bit mode this further involves
a certain amount of translation of the values.

Unfortunately internal sanity checking of these translated values
assumes high halves of registers to always be clear when invoking a
hypercall.  When this is found not to be the case, it triggers a
consistency check in the hypervisor and causes a crash.

Weakness: CWE-843 (Access of Resource Using Incompatible Type)

## Which versions are affected by CVE-2023-46842?

It affects 2 products.


Products: Fedoraproject Fedora, Xen Xen.

## How do I fix CVE-2023-46842?

Apply the vendor's patch.

## Is CVE-2023-46842 being exploited?

There is no known exploitation of CVE-2023-46842 in the wild and no public exploit code.

## Other vulnerabilities in Fedoraproject Fedora

- [CVE-2024-4577](https://insights.sbomify.com/CVE-2024-4577/): PHP-CGI OS Command Injection (critical 9.8, exploited in the wild)
- [CVE-2021-39226](https://insights.sbomify.com/CVE-2021-39226/): Grafana Authentication Bypass (critical 9.8, exploited in the wild)
- [CVE-2019-5544](https://insights.sbomify.com/CVE-2019-5544/): VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow (critical 9.8, exploited in the wild)
- [CVE-2024-4947](https://insights.sbomify.com/CVE-2024-4947/): Google Chromium V8 Type Confusion (critical 9.6, exploited in the wild)
- [CVE-2024-4671](https://insights.sbomify.com/CVE-2024-4671/): Google Chromium Visuals Use-After-Free (critical 9.6, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-46842 and fix it if it is affected.

What it is: CVE-2023-46842 is a medium-severity denial of service vulnerability in Fedoraproject Fedora, published on 16 May 2024. 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-2023-46842 in the wild and no public exploit code.

Affected product: Fedoraproject Fedora. 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-2023-46842/ (Markdown: https://insights.sbomify.com/CVE-2023-46842/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-46842
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-46842
- OSV: https://osv.dev/vulnerability/CVE-2023-46842

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-46842/
Summaries are generated and may contain mistakes; the official description above is the record.