CVE-2026-98720 (GCVE-0-2026-98720)
Vulnerability from cvelistv5
Published
2026-10-18 15:46
Modified
2026-10-19 09:24
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified Force a refresh of the vmcs02 MSR bitmap during nested VM-Enter if the runtime eVMCS controls (pin, primary, secondary, etc.) are being updated. If L1 isn't intercepting TPR writes, runs L2 with TPR virtualization, and then runs the same L2 with TPR virtualization disabled, KVM will fail to refresh msr_bitmap02 and leave TPR in passthrough mode even though TPR virtualization is disabled. I.e. failure to refresh the bitmap lets L2 (or L1 by proxy) read and write L0's TPR.
References
Impacted products
Vendor Product Version
Linux Linux Version: 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e
Version: 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e
Version: 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e
Version: 502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/vmx/nested.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2db11598b59f16ddb6420693f9a4ac4efc3d4789",
              "status": "affected",
              "version": "502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e",
              "versionType": "git"
            },
            {
              "lessThan": "f6189e26d0237e47e2f04f9cb1e43fd19a9b2f3a",
              "status": "affected",
              "version": "502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e",
              "versionType": "git"
            },
            {
              "lessThan": "1e497e3bdab6983deb68a1d26b488027deb4527f",
              "status": "affected",
              "version": "502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e",
              "versionType": "git"
            },
            {
              "lessThan": "2abb25273c82061dd4670690c81c319c03740bf6",
              "status": "affected",
              "version": "502d2bf5f2fd7c05adc2d4f057910bd5d4c4c63e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/vmx/nested.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "lessThan": "5.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.113",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.56",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "5.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified\n\nForce a refresh of the vmcs02 MSR bitmap during nested VM-Enter if the\nruntime eVMCS controls (pin, primary, secondary, etc.) are being updated.\nIf L1 isn\u0027t intercepting TPR writes, runs L2 with TPR virtualization, and\nthen runs the same L2 with TPR virtualization disabled, KVM will fail to\nrefresh msr_bitmap02 and leave TPR in passthrough mode even though TPR\nvirtualization is disabled.  I.e. failure to refresh the bitmap lets L2 (or\nL1 by proxy) read and write L0\u0027s TPR."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:24:31.090Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/2db11598b59f16ddb6420693f9a4ac4efc3d4789"
        },
        {
          "url": "https://git.kernel.org/stable/c/f6189e26d0237e47e2f04f9cb1e43fd19a9b2f3a"
        },
        {
          "url": "https://git.kernel.org/stable/c/1e497e3bdab6983deb68a1d26b488027deb4527f"
        },
        {
          "url": "https://git.kernel.org/stable/c/2abb25273c82061dd4670690c81c319c03740bf6"
        }
      ],
      "title": "KVM: nVMX: Force MSR bitmap refresh if runtime eVMCS controls are modified",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98720",
    "datePublished": "2026-10-18T15:46:55.863Z",
    "dateReserved": "2026-09-25T10:25:14.366Z",
    "dateUpdated": "2026-10-19T09:24:31.090Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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