CVE-2026-27211Cloud Hypervisor: Host File Exfiltration via QCOW Backing File Abuse
- 9.1CriticalCVSS base score
- 0.57%Exploitation in 30 daysEPSS · top 52% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By GitHub_M
- 3 days later
· 3 days later
Published
- 4 days later
· 4 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | Critical9.1 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H |
| NVDNVD · Analyzed | 4.0 | Critical9.1 | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.57% · top 52% of all CVEs (15 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.1.
Affected products
cloud-hypervisor · cloud-hypervisor
- affected >= 34.0, < 50.1
References
References7
- https://github.com/cloud-hypervisor/cloud-hypervisor/security/advisories/GHSA-jmr4-g2hv-mjj6 (opens in a new tab)x_refsource_CONFIRM
- https://github.com/cloud-hypervisor/cloud-hypervisor/commit/081a6ebb5184228ff348601502258f3f72bd8b43 (opens in a new tab)x_refsource_MISC
- https://github.com/cloud-hypervisor/cloud-hypervisor/commit/509832298b6865365b00bda88722e76e41ce7f41 (opens in a new tab)x_refsource_MISC
- https://github.com/cloud-hypervisor/cloud-hypervisor/commit/a63315df54e06f6ec867f17b63076c266e2d8648 (opens in a new tab)x_refsource_MISC
- https://github.com/cloud-hypervisor/cloud-hypervisor/commit/cb495959a8bea1b56e8fc82d15ba527a0e7fcf3c (opens in a new tab)x_refsource_MISC
- https://github.com/cloud-hypervisor/cloud-hypervisor/releases/tag/v50.1 (opens in a new tab)x_refsource_MISC
- https://github.com/cloud-hypervisor/cloud-hypervisor/releases/tag/v51.0 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-7729 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-27211)Record last updated .