CVE-2026-45782
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).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 4.0
- 8.9 HIGHCVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/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/M
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Source
- security-advisories@github.com
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
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.