> For the complete documentation index, see [llms.txt](https://docs.ionos.com/cloud/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ionos.com/cloud/security-safeguards/vulnerability-register/2025/cpu-vulnerabilities-vmscape.md).

# 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 VM 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 in the host. The attack affects all AMD processors from Zen 1 to Zen 5, and 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?

<code class="expression">space.vars.ionos\_cloud</code> 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. <code class="expression">space.vars.ionos\_cloud</code> 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).


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