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.
https://github.com/cloud-hypervisor/cloud-hypervisor/security/advisories/GHSA-f47p-p25q-83rh
https://github.com/cloud-hypervisor/cloud-hypervisor/releases/tag/v52.0
https://github.com/cloud-hypervisor/cloud-hypervisor/releases/tag/v51.2
https://github.com/cloud-hypervisor/cloud-hypervisor/pull/8220
https://github.com/cloud-hypervisor/cloud-hypervisor/commit/1314ac883c641f1045bbb06dec0de045a3894baa
Published: 2026-06-10
Updated: 2026-06-10
Base Score: 3.6
Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:P
Severity: Low
Base Score: 7.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Severity: High
Base Score: 8.9
Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
Severity: High
EPSS: 0.00014