{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64286", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.778Z", "datePublished": "2026-07-25T08:49:27.542Z", "dateUpdated": "2026-08-17T04:52:42.012Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:52:42.012Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU\n\nflush_hyp_vcpu() copies the host vCPU context into the hyp's private\nvCPU on every run. ctxt_to_vcpu() expects a guest context to have a\nNULL __hyp_running_vcpu, which is only ever set on the host context, so\nthat it resolves the vCPU via container_of(). While this is generally\nthe case, flush_hyp_vcpu() copies the context verbatim and does not\nenforce this, so a value provided by the host is dereferenced at EL2\n(host -> EL2).\n\nFix by clearing __hyp_running_vcpu after the copy." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H", "baseScore": 8.2, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - A malicious or compromised local EL1 host can place the pointer in the host vCPU context and trigger the vulnerable pKVM path through KVM_RUN; no remote input path reaches it.\nAC:L - The attacker-selected pointer is copied and dereferenced deterministically on every vCPU run, without a race, and EL2 addresses of host-donated metadata are derivable by the host.\nPR:H - Exploitation requires host-kernel control or an equivalent arbitrary kernel write. The KVM userspace register API does not expose __hyp_running_vcpu, and user namespaces do not bypass this restriction.\nUI:N - Once the malicious host context is prepared, invoking the vCPU run path requires no action by another user.\nS:C - The vulnerability crosses the intended isolation boundary from the untrusted EL1 host into the pKVM hypervisor at EL2 and can affect protected-VM resources.\nC:H - The forged pointer drives EL2-private memory dereferences during system-register restoration. Chaining these reads with the write-side corruption can compromise EL2 and expose hypervisor or protected-guest memory.\nI:H - The system-register save path can write through the attacker-selected vCPU pointer into EL2-accessible memory. This can corrupt trusted hypervisor metadata and plausibly enable control-flow or protected-guest state modification.\nA:H - An invalid or unmapped pointer causes a synchronous EL2 fault followed by the nVHE HYP panic handler, which explicitly panics the host kernel." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/kvm/hyp/nvhe/hyp-main.c" ], "versions": [ { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "477145860dba4c30f0b4e36f02f4c5291c1c888b", "status": "affected", "versionType": "git" }, { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "dfaef40d8a1533940fc1af788d70fce07362b4ce", "status": "affected", "versionType": "git" }, { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "6bea2f8becdb20d34378493c3b77a9b9cf8c6cfa", "status": "affected", "versionType": "git" }, { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "d4f4d61715d1061ba83b88196a3605662be30750", "status": "affected", "versionType": "git" }, { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "e8042f6e1d7befb2fb6b10a75918642bcd0acf9a", "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/arm64/kvm/hyp/nvhe/hyp-main.c" ], "versions": [ { "version": "6.2", "status": "affected" }, { "version": "0", "lessThan": "6.2", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.145", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.97", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "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": "6.2", "versionEndExcluding": "6.6.145" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.12.97" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/477145860dba4c30f0b4e36f02f4c5291c1c888b" }, { "url": "https://git.kernel.org/stable/c/dfaef40d8a1533940fc1af788d70fce07362b4ce" }, { "url": "https://git.kernel.org/stable/c/6bea2f8becdb20d34378493c3b77a9b9cf8c6cfa" }, { "url": "https://git.kernel.org/stable/c/d4f4d61715d1061ba83b88196a3605662be30750" }, { "url": "https://git.kernel.org/stable/c/e8042f6e1d7befb2fb6b10a75918642bcd0acf9a" } ], "title": "KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU", "x_generator": { "engine": "bippy-1.2.0" } } } }