CVE-2026-27211
February 21, 2026
Cloud Hypervisor is a Virtual Machine Monitor for Cloud workloads. Versions 34.0 through 50.0 arevulnerable to arbitrary host file exfiltration (constrained by process privileges) when using virtio-block devices backed by raw images. A malicious guest can overwrite its disk header with a crafted QCOW2 structure pointing to a sensitive host path. Upon the next VM boot or disk scan, the image format auto-detection parses this header and serves the host file's contents to the guest. Guest-initiated VM reboots are sufficient to trigger a disk scan and do not cause the Cloud Hypervisor process to exit. Therefore, a single VM can perform this attack without needing interaction from the management stack. Successful exploitation requires the backing image to be either writable by the guest or sourced from an untrusted origin. Deployments utilizing only trusted, read-only images are not affected. This issue has been fixed in version 50.1. To workaround, enable land lock sandboxing and restrict process privileges and access.
Affected Packages
https://github.com/cloud-hypervisor/cloud-hypervisor.git (GITHUB):
Affected version(s) >=v34.0 <v51.0Fix Suggestion:
Update to version v51.0Related ResourcesĀ (7)
https://github.com/cloud-hypervisor/cloud-hypervisor/commit/081a6ebb5184228ff348601502258f3f72bd8b43
https://github.com/cloud-hypervisor/cloud-hypervisor/commit/a63315df54e06f6ec867f17b63076c266e2d8648
https://github.com/cloud-hypervisor/cloud-hypervisor/commit/509832298b6865365b00bda88722e76e41ce7f41
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Contact UsCVSS v4
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
HIGH
CVSS v3
Base Score:
8.6
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Weakness Type (CWE)
External Control of File Name or Path
EPSS
Base Score:
0.05