# Advisory on VMScape CPU Vulnerability

## VMSCAPE vulnerablity affecting AMD and Intel CPUs

A team of researchers at ETH Zurich university, have developed a new attack called [<mark style="color:blue;">VMScape</mark>](https://comsec.ethz.ch/vmscape) that breaks the isolation between VMs and the cloud hypervisor, bypassing existing Spectre mitigations and threatening to leak sensitive data by leveraging speculative execution. Redhat has classified this vulnerabilities as having a **Moderate** severity score with a CVSS score **6.5**.

The exploit, called VMScape, exploits insufficient branch predictor isolation between a guest and a userspace hypervisor such as Quick Emulator (QEMU), allowing a malicious KVM guest to leak sensitive information. Cloud computing relies on virtualization to securely partition physical computing resources into virtual ones, which are managed by a hypervisor. VMSCAPE targets the Kernel Virtual Machine (KVM) and QEMU, as the hypervisor and the userspace component of the hypervisor, respectively, in the host. The attack affects all AMD processors from Zen 1 to Zen 5, as well as Intel’s “Coffee Lake” and older CPUs. The newer “Raptor Cove” and “Gracemont” are not impacted.

## What is the risk?

If an attacker exploits this vulnerability, they could exfiltrate information contained within different security contexts, such as other virtual machines or the host device itself.

## Impacted IONOS Cloud products

| Product Ranges   | Product                                                                                                             | Impacted | Mitigated | Patch Status |
| ---------------- | ------------------------------------------------------------------------------------------------------------------- | -------- | --------- | ------------ |
| Compute Services | [<mark style="color:blue;">Dedicated Core Servers</mark>](/cloud/compute-services/compute-engine/dedicated-core.md) | Yes      | Yes       | Done         |
| Compute Services | [<mark style="color:blue;">vCPU Servers</mark>](/cloud/compute-services/compute-engine/vcpu-server.md)              | Yes      | Yes       | Done         |
| Compute Services | [<mark style="color:blue;">Cubes</mark>](/cloud/compute-services/cubes.md)                                          | Yes      | Yes       | Done         |

## What action has IONOS Cloud taken to mitigate the severity?

IONOS Cloud is committed to the privacy and security of our customers' data. We are aware of this vulnerability and have already taken the required steps to mitigate this vulnerability. IONOS Cloud owns the patching responsibility, and no action is required from the customer.

## How can I get help?

If you have further questions or concerns about this vulnerability, contact [<mark style="color:blue;">IONOS Cloud Support</mark>](https://docs.ionos.com/cloud/support/general-information/contact-information).


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.ionos.com/cloud/security-safeguards/vulnerability-register/2025/cpu-vulnerabilities-vmscape.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.