CVE-2026-98637 (GCVE-0-2026-98637)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:20 – Updated: 2026-10-19 09:23
VLAI
Title
KVM: arm64: Do not clear VM-wide SVE feature on vCPU init failure
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Do not clear VM-wide SVE feature on vCPU init failure pkvm_vcpu_init_sve() clears KVM_ARM_VCPU_SVE in kvm->arch.vcpu_features when it fails, but vcpu_has_sve() tests KVM_ARCH_FLAG_GUEST_HAS_SVE, which is left set. Later vCPUs on that VM then skip the SVE setup and register with a NULL sve_state, which the guest's first FP access hands to sve_load_state(). Return the error without touching vcpu_features.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 7056 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 5db1bef933427aa467ad89c7b695a84a6b4afe16 , < bd46b41f412fb81c50bac1a0929ec31320f3a807 (git)
Affected: 5db1bef933427aa467ad89c7b695a84a6b4afe16 , < f0cd8ffae092cc1b9d7cfa9188ed5a88a374adcb (git)
Affected: 5db1bef933427aa467ad89c7b695a84a6b4afe16 , < a1b3c788ad31837e348075e93dbba3f447492776 (git)
guessed Create a notification for this product.
Linux Linux Affected: 6.16
Unaffected: 0 , < 6.16 (semver)
Unaffected: 6.18.55 , ≤ 6.18.* (semver)
Unaffected: 7.2.9 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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{
  "containers": {
    "cna": {
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        {
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          "product": "Linux",
          "programFiles": [
            "arch/arm64/kvm/hyp/nvhe/pkvm.c"
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              "versionType": "semver"
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                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Do not clear VM-wide SVE feature on vCPU init failure\n\npkvm_vcpu_init_sve() clears KVM_ARM_VCPU_SVE in kvm-\u003earch.vcpu_features\nwhen it fails, but vcpu_has_sve() tests KVM_ARCH_FLAG_GUEST_HAS_SVE,\nwhich is left set. Later vCPUs on that VM then skip the SVE setup and\nregister with a NULL sve_state, which the guest\u0027s first FP access hands\nto sve_load_state().\n\nReturn the error without touching vcpu_features."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:23:07.105Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        },
        {
          "url": "https://git.kernel.org/stable/c/a1b3c788ad31837e348075e93dbba3f447492776"
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      ],
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98637",
    "datePublished": "2026-10-18T15:20:08.157Z",
    "dateReserved": "2026-09-25T10:25:14.361Z",
    "dateUpdated": "2026-10-19T09:23:07.105Z",
    "state": "PUBLISHED"
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      "id": "msrc_CVE-2026-98637",
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      "product_status:under_investigation": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "KVM: arm64: Do not clear VM-wide SVE feature on vCPU init failure",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-98637.json",
      "version": "2"
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                ],
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        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: arm64: Do not clear VM-wide SVE feature on vCPU init failure\n\npkvm_vcpu_init_sve() clears KVM_ARM_VCPU_SVE in kvm-\u003earch.vcpu_features\nwhen it fails, but vcpu_has_sve() tests KVM_ARCH_FLAG_GUEST_HAS_SVE,\nwhich is left set. Later vCPUs on that VM then skip the SVE setup and\nregister with a NULL sve_state, which the guest\u0027s first FP access hands\nto sve_load_state().\n\nReturn the error without touching vcpu_features."
          }
        ],
        "id": "CVE-2026-98637",
        "lastModified": "2026-10-19T10:19:27.947",
        "metrics": {},
        "published": "2026-10-18T16:17:16.820",
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      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2026/cve-2026-98637.json",
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    }
  }
}



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