Vulnerability-Lookup

GHSA-H9FC-VQ2V-QF62

Vulnerability from github – Published: 2026-05-27 15:33 – Updated: 2026-06-24 18:32

Details

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

KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12

svm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB. However, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and clearing clean bits in vmcb12 is not architecturally defined.

Move vmcb_mark_dirty() to callers and drop it for vmcb12.

This also facilitates incoming refactoring that does not pass the entire VMCB to svm_copy_lbrs().

Severity

5.5 (Medium)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-46071"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:28Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nSVM: Avoid clearing VMCB_LBR in vmcb12\n\nsvm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB.\nHowever, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and\nclearing clean bits in vmcb12 is not architecturally defined.\n\nMove vmcb_mark_dirty() to callers and drop it for vmcb12.\n\nThis also facilitates incoming refactoring that does not pass the entire\nVMCB to svm_copy_lbrs().",
  "id": "GHSA-h9fc-vq2v-qf62",
  "modified": "2026-06-24T18:32:29Z",
  "published": "2026-05-27T15:33:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46071"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9efe23568806d1cd06f7d146f9b3037b8d585a9f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a3f0981a5a0e0bd51ad74cc7d9eed32294b24002"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b53ab5167a81537777ac780bbd93d32613aa3bda"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-46071 (GCVE-0-2026-46071)

Vulnerability from cvelistv5 – Published: 2026-05-27 12:57 – Updated: 2026-06-14 17:52

Title

KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12 svm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB. However, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and clearing clean bits in vmcb12 is not architecturally defined. Move vmcb_mark_dirty() to callers and drop it for vmcb12. This also facilitates incoming refactoring that does not pass the entire VMCB to svm_copy_lbrs().

Severity

No CVSS data available.

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/a3f0981a5a0e0bd51…
https://git.kernel.org/stable/c/9efe23568806d1cd0…
https://git.kernel.org/stable/c/b53ab5167a8153777…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: d20c796ca3709801f8a7fa36e8770a3dd8ebd34e , < a3f0981a5a0e0bd51ad74cc7d9eed32294b24002 (git) Affected: d20c796ca3709801f8a7fa36e8770a3dd8ebd34e , < 9efe23568806d1cd06f7d146f9b3037b8d585a9f (git) Affected: d20c796ca3709801f8a7fa36e8770a3dd8ebd34e , < b53ab5167a81537777ac780bbd93d32613aa3bda (git)
Linux	Linux	Affected: 5.19 Unaffected: 0 , < 5.19 (semver) Unaffected: 6.18.27 , ≤ 6.18.* (semver) Unaffected: 7.0.4 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/kvm/svm/nested.c",
            "arch/x86/kvm/svm/svm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "a3f0981a5a0e0bd51ad74cc7d9eed32294b24002",
              "status": "affected",
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              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "d20c796ca3709801f8a7fa36e8770a3dd8ebd34e",
              "versionType": "git"
            },
            {
              "lessThan": "b53ab5167a81537777ac780bbd93d32613aa3bda",
              "status": "affected",
              "version": "d20c796ca3709801f8a7fa36e8770a3dd8ebd34e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
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            "arch/x86/kvm/svm/svm.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.27",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.27",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
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                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nSVM: Avoid clearing VMCB_LBR in vmcb12\n\nsvm_copy_lbrs() always marks VMCB_LBR dirty in the destination VMCB.\nHowever, nested_svm_vmexit() uses it to copy LBRs to vmcb12, and\nclearing clean bits in vmcb12 is not architecturally defined.\n\nMove vmcb_mark_dirty() to callers and drop it for vmcb12.\n\nThis also facilitates incoming refactoring that does not pass the entire\nVMCB to svm_copy_lbrs()."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-14T17:52:10.514Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        },
        {
          "url": "https://git.kernel.org/stable/c/b53ab5167a81537777ac780bbd93d32613aa3bda"
        }
      ],
      "title": "KVM: nSVM: Avoid clearing VMCB_LBR in vmcb12",
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    "datePublished": "2026-05-27T12:57:57.316Z",
    "dateReserved": "2026-05-13T15:03:33.095Z",
    "dateUpdated": "2026-06-14T17:52:10.514Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
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}

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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

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