{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64287", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.778Z", "datePublished": "2026-07-25T08:49:28.168Z", "dateUpdated": "2026-08-17T04:52:43.106Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:52:43.106Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU\n\nflush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU\non every run. The vGIC list register save and restore use used_lrs as\ntheir loop bound and expect it to stay within the number of implemented\nlist registers. While this is generally the case, flush_hyp_vcpu()\ncopies vgic_v3 verbatim and does not enforce this, so a value provided\nby the host is used at EL2 to index vgic_lr[] and access ICH_LR_EL2\n(host -> EL2).\n\nFix by clamping used_lrs to the number of implemented list registers\nafter the copy, as the trusted path already does in\nvgic_flush_lr_state(). The number of implemented list registers is\nconstant after init, so it is replicated once from\nkvm_vgic_global_state.nr_lr into hyp_gicv3_nr_lr rather than read on\nevery entry." } ], "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 arm64 EL1 host reaches the flaw through the local KVM vCPU-run hypercall into pKVM EL2. No network or adjacent protocol directly controls this internal field.\nAC:L - On a pKVM/GICv3 system, the host can directly select an oversized used_lrs value and deterministically trigger the unchecked loops. No race or condition outside the attacker's control is required.\nPR:H - Normal KVM paths keep used_lrs hardware-bounded, and neither an unprivileged KVM user nor a user namespace can assign it directly. Exploitation requires control of the host kernel at EL1, equivalent to real administrative privileges.\nUI:N - The malicious host can load and run a vCPU itself without any action by a protected-VM user or another victim.\nS:C - Exploitation crosses pKVM's EL1-host-to-EL2 isolation boundary and can affect hypervisor-private state and protected VMs outside the host's security authority.\nC:H - The restore and synchronization paths can read beyond vgic_lr[] and transfer hyp-private vCPU data back into host-visible memory. EL2 compromise could expose protected-VM memory and other hypervisor secrets.\nI:H - The save path writes beyond vgic_lr[] into adjacent hyp-private vCPU metadata, including pointer, lock, and list state. This memory corruption is plausibly usable for EL2 control-flow hijacking and protected-VM modification.\nA:H - Large bounds can cause extensive loops, invalid EL2 memory accesses, or corruption of critical hypervisor metadata. An nVHE hypervisor panic explicitly escalates to a host kernel panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "arch/arm64/include/asm/kvm_hyp.h", "arch/arm64/kvm/arm.c", "arch/arm64/kvm/hyp/nvhe/hyp-main.c" ], "versions": [ { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8", "status": "affected", "versionType": "git" }, { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "9fa301d8298778dd799fa4dcf7a7f440715d146e", "status": "affected", "versionType": "git" }, { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "c646431865f4b1a5b14067233fa27b11e05e0d46", "status": "affected", "versionType": "git" }, { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "7fca3fcef81c713bc82a37bf741e0f28e6d04a6f", "status": "affected", "versionType": "git" }, { "version": "be66e67f175096f283c9d5614c4991fc9e7ed975", "lessThan": "8cc8bbbfab14c22c5551d0dd19b208a44b141c76", "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/include/asm/kvm_hyp.h", "arch/arm64/kvm/arm.c", "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": "6.18.40", "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": "6.18.40" }, { "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/2c5e72b9fbf83fdfa724e9f1af0f418ccf8739b8" }, { "url": "https://git.kernel.org/stable/c/9fa301d8298778dd799fa4dcf7a7f440715d146e" }, { "url": "https://git.kernel.org/stable/c/c646431865f4b1a5b14067233fa27b11e05e0d46" }, { "url": "https://git.kernel.org/stable/c/7fca3fcef81c713bc82a37bf741e0f28e6d04a6f" }, { "url": "https://git.kernel.org/stable/c/8cc8bbbfab14c22c5551d0dd19b208a44b141c76" } ], "title": "KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU", "x_generator": { "engine": "bippy-1.2.0" } } } }