CVE-2026-27211

Host file disclosure via crafted QCOW backing path

Published Feb 21, 2026 · Updated Feb 21, 2026

Information disclosure in Cloud Hypervisor 34.0 through 50.0 allows guest OS users to read host files through virtio-block disks. Image-format auto-detection accepts a guest-written QCOW2 header, follows its attacker-controlled backing-file path, and serves that host file as disk data. Exploitation requires a guest-writable or untrusted raw backing image and a reboot or disk scan; access is limited to files readable by the hypervisor process.

CVSS severity7.2
High
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Cloud Hypervisor 34.0 through 50.0 allows guest OS users to read host files through virtio-block disks. Image-format auto-detection accepts a guest-written QCOW2 header, follows its attacker-controlled backing-file path, and serves that host file as disk data. Exploitation requires a guest-writable or untrusted raw backing image and a reboot or disk scan; access is limited to files readable by the hypervisor process.

The record

CVE
CVE-2026-27211
Published
Feb 21, 2026
Updated
Feb 21, 2026
Vendor
Cloud Hypervisor
Product
Cloud Hypervisor
Classifications
CWE-73, T1005
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 34.0, < 50.1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Cloud Hypervisor · Cloud Hypervisorversion=>= 34.0, < 50.1

Published CVSS scores

10.0NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
7.2Cloud Hypervisor GitHub Security AdvisoryCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H
9.1GitHub, Inc. CNACVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-73External Control of File Name or Path
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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