Vulnerability-Lookup

CVE-2026-64284 (GCVE-0-2026-64284)

Vulnerability from cvelistv5 – Published: 2026-07-25 08:49 – Updated: 2026-07-25 08:49

Title

KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty. Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.

Severity

No CVSS data available.

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/b3436d9b9b1affe1c…
https://git.kernel.org/stable/c/4ad73ef0e7966ecfe…
https://git.kernel.org/stable/c/f2ca2b5326211bd38…
https://git.kernel.org/stable/c/0ffedf43910e44b76…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: f7f39c50edb9d336274371953275e0d3503b9b75 , < b3436d9b9b1affe1c3191ac9831308923f5f03c3 (git) Affected: f7f39c50edb9d336274371953275e0d3503b9b75 , < 4ad73ef0e7966ecfe67de0060537b4cb14d9acd4 (git) Affected: f7f39c50edb9d336274371953275e0d3503b9b75 , < f2ca2b5326211bd38490f0497eb583721ce0bbc0 (git) Affected: f7f39c50edb9d336274371953275e0d3503b9b75 , < 0ffedf43910e44b76c2c1db4e9fbf12b268190c1 (git)
Linux	Linux	Affected: 6.12 Unaffected: 0 , < 6.12 (semver) Unaffected: 6.12.96 , ≤ 6.12.* (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/svm/svm.c",
            "arch/x86/kvm/vmx/vmx.c",
            "arch/x86/kvm/x86.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "f7f39c50edb9d336274371953275e0d3503b9b75",
              "versionType": "git"
            },
            {
              "lessThan": "4ad73ef0e7966ecfe67de0060537b4cb14d9acd4",
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              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "f7f39c50edb9d336274371953275e0d3503b9b75",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "f7f39c50edb9d336274371953275e0d3503b9b75",
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        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/svm/svm.c",
            "arch/x86/kvm/vmx/vmx.c",
            "arch/x86/kvm/x86.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "lessThan": "6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
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              "version": "6.12.96",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
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                  "versionStartIncluding": "6.12",
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                },
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                  "versionStartIncluding": "6.12",
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              "negate": false,
              "operator": "OR"
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      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Ensure vendor\u0027s exit handler runs before fastpath userspace exits\n\nMove the handling of fastpath userspace exits into vendor code to ensure\nKVM runs vendor specific operations that need to run before userspace gains\ncontrol of the vCPU.  E.g. for VMX (and soon to be for SVM as well), KVM\nneeds to flush the PML buffer prior to exiting to userspace, otherwise any\nmemory written by the final KVM_RUN might never be flagged as dirty.\n\nNote, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in\ngeneral, as that risks consuming stale state in a fastpath handler.  That\nwill be addressed in a future change."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-25T08:49:26.270Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
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          "url": "https://git.kernel.org/stable/c/b3436d9b9b1affe1c3191ac9831308923f5f03c3"
        },
        {
          "url": "https://git.kernel.org/stable/c/4ad73ef0e7966ecfe67de0060537b4cb14d9acd4"
        },
        {
          "url": "https://git.kernel.org/stable/c/f2ca2b5326211bd38490f0497eb583721ce0bbc0"
        },
        {
          "url": "https://git.kernel.org/stable/c/0ffedf43910e44b76c2c1db4e9fbf12b268190c1"
        }
      ],
      "title": "KVM: x86: Ensure vendor\u0027s exit handler runs before fastpath userspace exits",
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      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64284",
    "datePublished": "2026-07-25T08:49:26.270Z",
    "dateReserved": "2026-07-19T15:36:31.777Z",
    "dateUpdated": "2026-07-25T08:49:26.270Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-64284",
      "date": "2026-07-26",
      "epss": "0.002",
      "percentile": "0.10118"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-64284\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-07-25T10:17:09.033\",\"lastModified\":\"2026-07-25T10:17:09.033\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nKVM: x86: Ensure vendor\u0027s exit handler runs before fastpath userspace exits\\n\\nMove the handling of fastpath userspace exits into vendor code to ensure\\nKVM runs vendor specific operations that need to run before userspace gains\\ncontrol of the vCPU.  E.g. for VMX (and soon to be for SVM as well), KVM\\nneeds to flush the PML buffer prior to exiting to userspace, otherwise any\\nmemory written by the final KVM_RUN might never be flagged as dirty.\\n\\nNote, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in\\ngeneral, as that risks consuming stale state in a fastpath handler.  That\\nwill be addressed in a future change.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"arch/x86/kvm/svm/svm.c\",\"arch/x86/kvm/vmx/vmx.c\",\"arch/x86/kvm/x86.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"f7f39c50edb9d336274371953275e0d3503b9b75\",\"lessThan\":\"b3436d9b9b1affe1c3191ac9831308923f5f03c3\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f39c50edb9d336274371953275e0d3503b9b75\",\"lessThan\":\"4ad73ef0e7966ecfe67de0060537b4cb14d9acd4\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f39c50edb9d336274371953275e0d3503b9b75\",\"lessThan\":\"f2ca2b5326211bd38490f0497eb583721ce0bbc0\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"f7f39c50edb9d336274371953275e0d3503b9b75\",\"lessThan\":\"0ffedf43910e44b76c2c1db4e9fbf12b268190c1\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"arch/x86/kvm/svm/svm.c\",\"arch/x86/kvm/vmx/vmx.c\",\"arch/x86/kvm/x86.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"6.12\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"6.12\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.96\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.39\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.4\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2-rc1\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0ffedf43910e44b76c2c1db4e9fbf12b268190c1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4ad73ef0e7966ecfe67de0060537b4cb14d9acd4\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/b3436d9b9b1affe1c3191ac9831308923f5f03c3\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f2ca2b5326211bd38490f0497eb583721ce0bbc0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "suse_vex": {
      "aggregate_severity": "not set",
      "current_release_date": "2026-07-25T16:46:36Z",
      "cve": "CVE-2026-64284",
      "id": "CVE-2026-64284",
      "initial_release_date": "2026-07-25T16:46:36Z",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-64284",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-64284.json",
      "version": "2"
    }
  }
}

GHSA-GV38-JCPJ-J76H

Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31

Details

In the Linux kernel, the following vulnerability has been resolved:

KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits

Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty.

Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-64284"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-25T10:17:09Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Ensure vendor\u0027s exit handler runs before fastpath userspace exits\n\nMove the handling of fastpath userspace exits into vendor code to ensure\nKVM runs vendor specific operations that need to run before userspace gains\ncontrol of the vCPU.  E.g. for VMX (and soon to be for SVM as well), KVM\nneeds to flush the PML buffer prior to exiting to userspace, otherwise any\nmemory written by the final KVM_RUN might never be flagged as dirty.\n\nNote, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in\ngeneral, as that risks consuming stale state in a fastpath handler.  That\nwill be addressed in a future change.",
  "id": "GHSA-gv38-jcpj-j76h",
  "modified": "2026-07-25T12:31:29Z",
  "published": "2026-07-25T12:31:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64284"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0ffedf43910e44b76c2c1db4e9fbf12b268190c1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4ad73ef0e7966ecfe67de0060537b4cb14d9acd4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b3436d9b9b1affe1c3191ac9831308923f5f03c3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f2ca2b5326211bd38490f0497eb583721ce0bbc0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

CVE-2026-64284 (GCVE-0-2026-64284)

GHSA-GV38-JCPJ-J76H

Tags

Sightings

Nomenclature