{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-98638", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.361Z", "datePublished": "2026-10-18T15:20:09.380Z", "dateUpdated": "2026-10-19T09:23:08.052Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:23:08.052Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()\n\npkvm_vcpu_init_sve() clamps only the upper bound of the host-provided\nsve_max_vl, so an invalid vector length reaches sve_state_size_from_vl()\nand the WARN_ON() there, which is fatal at EL2. The existing\n!sve_state_size test rejects such a length, but only after the macro has\nrun.\n\nCheck sve_vl_valid() before deriving the state size. A valid length\ncannot yield a zero size, so the !sve_state_size test goes with it."}], "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/pkvm.c"], "versions": [{"version": "5db1bef933427aa467ad89c7b695a84a6b4afe16", "lessThan": "faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc", "status": "affected", "versionType": "git"}, {"version": "5db1bef933427aa467ad89c7b695a84a6b4afe16", "lessThan": "bae3e4493046de4fefa15f809d9b8dc114e84a3d", "status": "affected", "versionType": "git"}, {"version": "5db1bef933427aa467ad89c7b695a84a6b4afe16", "lessThan": "2a2eb10795a1e495aebc7f829ccecb72c05b4fd9", "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/pkvm.c"], "versions": [{"version": "6.16", "status": "affected"}, {"version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.55", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.9", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "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": "6.16", "versionEndExcluding": "6.18.55"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.2.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc"}, {"url": "https://git.kernel.org/stable/c/bae3e4493046de4fefa15f809d9b8dc114e84a3d"}, {"url": "https://git.kernel.org/stable/c/2a2eb10795a1e495aebc7f829ccecb72c05b4fd9"}], "title": "KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["arch/arm64/kvm/hyp/nvhe/pkvm.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc", "status": "affected", "version": "5db1bef933427aa467ad89c7b695a84a6b4afe16", "versionType": "git"}, {"lessThan": "bae3e4493046de4fefa15f809d9b8dc114e84a3d", "status": "affected", "version": "5db1bef933427aa467ad89c7b695a84a6b4afe16", "versionType": "git"}, {"lessThan": "2a2eb10795a1e495aebc7f829ccecb72c05b4fd9", "status": "affected", "version": "5db1bef933427aa467ad89c7b695a84a6b4afe16", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["arch/arm64/kvm/hyp/nvhe/pkvm.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.16"}, {"lessThan": "6.16", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.55", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()\n\npkvm_vcpu_init_sve() clamps only the upper bound of the host-provided\nsve_max_vl, so an invalid vector length reaches sve_state_size_from_vl()\nand the WARN_ON() there, which is fatal at EL2. The existing\n!sve_state_size test rejects such a length, but only after the macro has\nrun.\n\nCheck sve_vl_valid() before deriving the state size. A valid length\ncannot yield a zero size, so the !sve_state_size test goes with it."}], "id": "CVE-2026-98638", "lastModified": "2026-10-19T10:19:28.037", "metrics": {}, "published": "2026-10-18T16:17:16.920", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2a2eb10795a1e495aebc7f829ccecb72c05b4fd9"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bae3e4493046de4fefa15f809d9b8dc114e84a3d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/faf66e55e87498ab4bf88cdf9a629e61b3f2d3bc"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: KVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()", "id": "2554980", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2554980"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-617", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nKVM: arm64: Validate the SVE vector length in pkvm_vcpu_init_sve()\npkvm_vcpu_init_sve() clamps only the upper bound of the host-provided\nsve_max_vl, so an invalid vector length reaches sve_state_size_from_vl()\nand the WARN_ON() there, which is fatal at EL2. The existing\n!sve_state_size test rejects such a length, but only after the macro has\nrun.\nCheck sve_vl_valid() before deriving the state size. A valid length\ncannot yield a zero size, so the !sve_state_size test goes with it.", "A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem on ARM64 systems. This vulnerability can lead to a Denial of Service (DoS) by causing a fatal hypervisor crash. The Protected KVM (pKVM) hypervisor does not properly validate the Scalable Vector Extension (SVE) vector length parameter during virtual CPU initialization. A local user with host privileges can exploit this flaw by providing an invalid vector length, triggering a fatal condition at the hypervisor level that halts the system."], "name": "CVE-2026-98638", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Not affected", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-10-18T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-98638\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-98638\nhttps://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98638.mbox"], "threat_severity": "Moderate"}