What’s Vulnerable › Vulnerabilities

CVE-2026-45782: Cloud Hypervisor: Use-after-free in virtio-block Async I/O Completion

• Severity: high (CVSS 8.9 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-10 · updated 2026-07-23
• Weakness: CWE-416

Description

Cloud Hypervisor is a Virtual Machine Monitor for Cloud workloads. From version 21.0 to before version 51.2, a guest can cause a use-after-free in the cloud-hypervisor process by submitting two virtio-block descriptor chains that reuse the same head_index while asynchronous block I/O is enabled (e.g. io_uring, aio). When the kernel completes the duplicate operation before the original, the completion path frees a bounce buffer that the kernel is still actively reading from or writing to, corrupting the freed memory. This issue has been patched in versions 51.2 and 52.0.

Affected products

• cloud-hypervisor: from 21.0, < 51.2

References

• https://github.com/cloud-hypervisor/cloud-hypervisor/commit/1314ac883c641f1045bbb06dec0de045a3894baa
• https://github.com/cloud-hypervisor/cloud-hypervisor/pull/8220
• https://github.com/cloud-hypervisor/cloud-hypervisor/releases/tag/v51.2
• https://github.com/cloud-hypervisor/cloud-hypervisor/releases/tag/v52.0
• https://github.com/cloud-hypervisor/cloud-hypervisor/security/advisories/GHSA-f47p-p25q-83rh

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