Malicious HTTP requests could close arbitrary opening file descriptors in cloud-hypervisor
Cloud hypervisor is a Virtual Machine Monitor for Cloud workloads. This vulnerability allows users to close arbitrary open file descriptors in the Cloud Hypervisor process via sending malicious HTTP request through the HTTP API socket. As a result, the Cloud Hypervisor process can be easily crashed, causing Deny-of-Service (DoS). This can also be a potential Use-After-Free (UAF) vulnerability. Users require to have the write access to the API socket file to trigger this vulnerability. Impacted versions of Cloud Hypervisor include upstream main branch, v31.0, and v30.0. The vulnerability was initially detected by our `http_api_fuzzer` via oss-fuzz. This issue has been addressed in versions 30.1 and 31.1. Users unable to upgrade may mitigate this issue by ensuring the write access to the API socket file is granted to trusted users only.
- Published
- Apr 19, 2023
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 27th percentile
- CWE
- CWE-306
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Report tools
Action score
19
Monitor
Low priority for now.
- CVSS
- 19 / 40 · 4.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 4.9
- CNA · GitHub_M
- 4.0
- 0.9 point gap
CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:L
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| cloudhypervisor | cloud hypervisor | cpe:2.3:a:cloudhypervisor:cloud_hypervisor |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- cloudhypervisor cloud hypervisor30.0
- cloudhypervisor cloud hypervisor31.1
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
cloud-hypervisor cloud-hypervisor
- >= 30.0, < 30.1, >= 31.0, < 31.1affected
Same product
cloudhypervisor: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-27211Cloud Hypervisor: Host File Exfiltration via QCOW Backing File Abuse36Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- Administrator privileges are required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-306 · Missing Authentication for Critical FunctionCVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Root cause
A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”
The bug in code
The whole CWE-306 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
// Added for the support teamapp.post("/maintenance/reset", resetDevice);Fixed
if (config.maintenanceEnabled) { app.post( "/maintenance/reset", requireSession, requireRole("admin"), resetDevice );}Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
- github.com/cloud-hypervisor/cloud-hypervisor/pull/5350
- github.com/cloud-hypervisor/cloud-hypervisor/pull/5373
- github.com/cloud-hypervisor/cloud-hypervisor/security/advisories/GHSA-g6mw-f26h-4jgp
- oss-fuzz.com/testcase-detail/5260873569796096
- oss-fuzz.com/testcase-detail/5426283514560512
Vendor advisories and official records. Exploit/PoC links are deliberately left out.