{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2\n\nAfter VMRUN in guest mode, nested_sync_control_from_vmcb02() syncs\nfields written by the CPU from vmcb02 to the cached vmcb12. This is\nbecause the cached vmcb12 is used as the authoritative copy of some of\nthe controls, and is the payload when saving/restoring nested state.\n\nint_state is also written by the CPU, specifically bit 0 (i.e.\nSVM_INTERRUPT_SHADOW_MASK) for nested VMs, but it is not sync\u0027d to\ncached vmcb12. This does not cause a problem if KVM_SET_NESTED_STATE\npreceeds KVM_SET_VCPU_EVENTS in the restore path, as an interrupt shadow\nwould be correctly restored to vmcb02 (KVM_SET_VCPU_EVENTS overwrites\nwhat KVM_SET_NESTED_STATE restored in int_state).\n\nHowever, if KVM_SET_VCPU_EVENTS preceeds KVM_SET_NESTED_STATE, an\ninterrupt shadow would be restored into vmcb01 instead of vmcb02. This\nwould mostly be benign for L1 (delays an interrupt), but not for L2. For\nL2, the vCPU could hang (e.g. if a wakeup interrupt is delivered before\na HLT that should have been in an interrupt shadow).\n\nSync int_state to the cached vmcb12 in nested_sync_control_from_vmcb02()\nto avoid this problem. With that, KVM_SET_NESTED_STATE restores the\ncorrect interrupt shadow state, and if KVM_SET_VCPU_EVENTS follows it\nwould overwrite it with the same value."
    }
  ],
  "id": "CVE-2026-45987",
  "lastModified": "2026-05-27T14:48:03.013",
  "metrics": {},
  "published": "2026-05-27T14:17:16.113",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/03bee264f8ebfd39e0254c98e112d033a7aa9055"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1709418535a8df95532999d61b03d59975280258"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2f950eeb27af6885416232761700b8820cae0a61"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/497f6af9679fc9c6ce2f438e11ed5d51b1aa8297"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e0377e52f3c10ee572732d11b04625b7f517a862"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-45987"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-27T14:17:16Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2\n\nAfter VMRUN in guest mode, nested_sync_control_from_vmcb02() syncs\nfields written by the CPU from vmcb02 to the cached vmcb12. This is\nbecause the cached vmcb12 is used as the authoritative copy of some of\nthe controls, and is the payload when saving/restoring nested state.\n\nint_state is also written by the CPU, specifically bit 0 (i.e.\nSVM_INTERRUPT_SHADOW_MASK) for nested VMs, but it is not sync\u0027d to\ncached vmcb12. This does not cause a problem if KVM_SET_NESTED_STATE\npreceeds KVM_SET_VCPU_EVENTS in the restore path, as an interrupt shadow\nwould be correctly restored to vmcb02 (KVM_SET_VCPU_EVENTS overwrites\nwhat KVM_SET_NESTED_STATE restored in int_state).\n\nHowever, if KVM_SET_VCPU_EVENTS preceeds KVM_SET_NESTED_STATE, an\ninterrupt shadow would be restored into vmcb01 instead of vmcb02. This\nwould mostly be benign for L1 (delays an interrupt), but not for L2. For\nL2, the vCPU could hang (e.g. if a wakeup interrupt is delivered before\na HLT that should have been in an interrupt shadow).\n\nSync int_state to the cached vmcb12 in nested_sync_control_from_vmcb02()\nto avoid this problem. With that, KVM_SET_NESTED_STATE restores the\ncorrect interrupt shadow state, and if KVM_SET_VCPU_EVENTS follows it\nwould overwrite it with the same value.",
  "id": "GHSA-x4f8-qj9g-g99w",
  "modified": "2026-05-27T15:33:19Z",
  "published": "2026-05-27T15:33:19Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45987"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/03bee264f8ebfd39e0254c98e112d033a7aa9055"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1709418535a8df95532999d61b03d59975280258"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2f950eeb27af6885416232761700b8820cae0a61"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/497f6af9679fc9c6ce2f438e11ed5d51b1aa8297"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e0377e52f3c10ee572732d11b04625b7f517a862"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

{
  "document": {
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2026-45987 KVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2 - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-45987.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "KVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2",
    "tracking": {
      "current_release_date": "2026-05-28T14:41:52.000Z",
      "generator": {
        "date": "2026-05-29T07:23:45.829Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-45987",
      "initial_release_date": "2026-05-02T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-05-28T01:10:46.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2026-05-28T14:41:52.000Z",
          "legacy_version": "2",
          "number": "2",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "3.0",
                "product": {
                  "name": "Azure Linux 3.0",
                  "product_id": "17084"
                }
              }
            ],
            "category": "product_name",
            "name": "Azure Linux"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "azl3 kernel 0:6.6.139.1-1.azl3",
                "product": {
                  "name": "azl3 kernel 0:6.6.139.1-1.azl3",
                  "product_id": "1"
                }
              }
            ],
            "category": "product_name",
            "name": "kernel"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "azl3 kernel 0:6.6.139.1-1.azl3 as a component of Azure Linux 3.0",
          "product_id": "17084-1"
        },
        "product_reference": "1",
        "relates_to_product_reference": "17084"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-45987",
      "notes": [
        {
          "category": "general",
          "text": "Linux",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "known_affected": [
          "17084-1"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-45987 KVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2 - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-45987.json"
        }
      ],
      "remediations": [
        {
          "category": "none_available",
          "date": "2026-05-28T01:10:46.000Z",
          "details": "There is no fix available for this vulnerability as of now",
          "product_ids": [
            "17084-1"
          ]
        }
      ],
      "title": "KVM: nSVM: Sync interrupt shadow to cached vmcb12 after VMRUN of L2"
    }
  ]
}