{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64562", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.796Z", "datePublished": "2026-08-04T06:23:21.855Z", "dateUpdated": "2026-08-19T16:28:32.954Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-19T16:28:32.954Z" }, "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": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "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." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/x86/kvm/vmx/nested.c" ], "versions": [ { "version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5", "lessThan": "b82c3144d8264265448292ca406f60bafeba3b6f", "status": "affected", "versionType": "git" }, { "version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5", "lessThan": "4f50e6aec16f69627dbad5704d1e90a255d766a7", "status": "affected", "versionType": "git" }, { "version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5", "lessThan": "dc3eecfa219ebc9d01eaf7d1abd1441efe884dab", "status": "affected", "versionType": "git" }, { "version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5", "lessThan": "af56298e9d86e6098cd1d2e155cb2949b7c45412", "status": "affected", "versionType": "git" }, { "version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5", "lessThan": "589419470030a89f16cf19300658b6dc644ca946", "status": "affected", "versionType": "git" }, { "version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5", "lessThan": "8001d2ce9d9bd09118ce523aef595aa094573ae3", "status": "affected", "versionType": "git" }, { "version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5", "lessThan": "1dabef6e206568bf9d9ade74f6e56a48ea35695d", "status": "affected", "versionType": "git" }, { "version": "355f4fb1405ec29d0fac49b4d41fcd78cbd455d5", "lessThan": "622ebfac01ba4f9c0060cebd41257fe46fc4a0b3", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/x86/kvm/vmx/nested.c" ], "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "lessThan": "4.9", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.265", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.216", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.183", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.10.265" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.15.216" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.1.183" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.12.101" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "7.2" } ] } ] } ], "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" } } } }