CVE-2026-64562 (GCVE-0-2026-64562)
Vulnerability from cvelistv5
Published
2026-08-04 06:23
Modified
2026-08-19 16:28
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 Version: 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 Version: 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 Version: 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 Version: 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 Version: 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 Version: 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 Version: 355f4fb1405ec29d0fac49b4d41fcd78cbd455d5 |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/x86/kvm/vmx/nested.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "b82c3144d8264265448292ca406f60bafeba3b6f",
"status": "affected",
"version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5",
"versionType": "git"
},
{
"lessThan": "4f50e6aec16f69627dbad5704d1e90a255d766a7",
"status": "affected",
"version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5",
"versionType": "git"
},
{
"lessThan": "dc3eecfa219ebc9d01eaf7d1abd1441efe884dab",
"status": "affected",
"version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5",
"versionType": "git"
},
{
"lessThan": "af56298e9d86e6098cd1d2e155cb2949b7c45412",
"status": "affected",
"version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5",
"versionType": "git"
},
{
"lessThan": "589419470030a89f16cf19300658b6dc644ca946",
"status": "affected",
"version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5",
"versionType": "git"
},
{
"lessThan": "8001d2ce9d9bd09118ce523aef595aa094573ae3",
"status": "affected",
"version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5",
"versionType": "git"
},
{
"lessThan": "1dabef6e206568bf9d9ade74f6e56a48ea35695d",
"status": "affected",
"version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5",
"versionType": "git"
},
{
"lessThan": "622ebfac01ba4f9c0060cebd41257fe46fc4a0b3",
"status": "affected",
"version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"arch/x86/kvm/vmx/nested.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.9"
},
{
"lessThan": "4.9",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.148",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.101",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.42",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.265",
"versionStartIncluding": "4.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.216",
"versionStartIncluding": "4.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.183",
"versionStartIncluding": "4.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.148",
"versionStartIncluding": "4.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.101",
"versionStartIncluding": "4.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.42",
"versionStartIncluding": "4.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.6",
"versionStartIncluding": "4.9",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "4.9",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nVMX: Hide shadow VMCS right after VMCLEAR\n\nfree_nested() frees the shadow VMCS while vmcs01 still points to it. But\nbecause it is asynchronous with respect to loaded_vmcs_clear(), the vCPU\nmight migrate before the pointer is cleared and __loaded_vmcs_clear()\nmay then execute VMCLEAR.\n\nThe VMCS needs to stay attached until its explicit VMCLEAR completes, but\nthen it can be hidden and the page safely freed."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The bug is reached through local KVM nested VMX: open /dev/kvm, run a nested guest, then tear down nested state (VMXOFF/handle_vmxoff or vmx_leave_nested). It is not reachable via network or adjacent-radio packets.\nAC:L - A KVM VMM attacker controls both sides of the race by driving nested teardown (VMXOFF/vcpu destroy) while forcing vCPU migration via thread affinity/scheduling so __loaded_vmcs_clear() VMCLEARs the dangling shadow VMCS pointer.\nPR:L - Exploitation needs permission to use /dev/kvm and nested VMX (commonly kvm-group or equivalent), not real init-namespace root; KVM create/run ioctls have no CAP_SYS_ADMIN gate on this path.\nUI:N - After the attacker has KVM/nested access, they trigger free_nested and migration themselves; no separate victim action is required.\nS:C - free_nested runs in host KVM while handling L1 nested VMX teardown, and the UAF corrupts host kernel memory, crossing the guest/hypervisor isolation boundary (guest-to-host escape class).\nC:H - The dangling shadow VMCS pointer lets VMCLEAR operate on a freed page that may be reused, yielding a host kernel use-after-free that can be leveraged for arbitrary information disclosure.\nI:H - VMCLEAR writes VMCS state into the freed page; with page reuse this is host heap corruption enabling write primitives and potential host code execution, consistent with UAF guidance.\nA:H - Use-after-free of the shadow VMCS page can oops/panic the host kernel when VMCLEAR or later accessors touch reallocated memory, fully denying host availability."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-19T16:28:32.954Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/b82c3144d8264265448292ca406f60bafeba3b6f"
},
{
"url": "https://git.kernel.org/stable/c/4f50e6aec16f69627dbad5704d1e90a255d766a7"
},
{
"url": "https://git.kernel.org/stable/c/dc3eecfa219ebc9d01eaf7d1abd1441efe884dab"
},
{
"url": "https://git.kernel.org/stable/c/af56298e9d86e6098cd1d2e155cb2949b7c45412"
},
{
"url": "https://git.kernel.org/stable/c/589419470030a89f16cf19300658b6dc644ca946"
},
{
"url": "https://git.kernel.org/stable/c/8001d2ce9d9bd09118ce523aef595aa094573ae3"
},
{
"url": "https://git.kernel.org/stable/c/1dabef6e206568bf9d9ade74f6e56a48ea35695d"
},
{
"url": "https://git.kernel.org/stable/c/622ebfac01ba4f9c0060cebd41257fe46fc4a0b3"
}
],
"title": "KVM: nVMX: Hide shadow VMCS right after VMCLEAR",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-64562",
"datePublished": "2026-08-04T06:23:21.855Z",
"dateReserved": "2026-07-19T15:36:31.796Z",
"dateUpdated": "2026-08-19T16:28:32.954Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…