{
  "document": {
    "aggregate_severity": {
      "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
      "text": "Important"
    },
    "category": "csaf_security_advisory",
    "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"
      },
      {
        "category": "general",
        "text": "Required. The vulnerability documented by this CVE requires customer action to resolve.",
        "title": "Customer Action"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2025-21335 Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21335"
      },
      {
        "category": "self",
        "summary": "CVE-2025-21335 Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2025/msrc_cve-2025-21335.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Exploitability Index",
        "url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1"
      },
      {
        "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": "Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability",
    "tracking": {
      "current_release_date": "2025-01-15T00:00:00.000Z",
      "generator": {
        "date": "2026-04-02T00:47:54.439Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2025-21335",
      "initial_release_date": "2025-01-14T00:00:00.000Z",
      "revision_history": [
        {
          "date": "2025-01-14T00:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2025-01-15T00:00:00.000Z",
          "legacy_version": "1.1",
          "number": "2",
          "summary": "Added FAQ information. This is an informational change only."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.19044.5371",
            "product": {
              "name": "Windows 10 Version 21H2 for x64-based Systems \u003c10.0.19044.5371",
              "product_id": "11"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.19044.5371",
            "product": {
              "name": "Windows 10 Version 21H2 for x64-based Systems 10.0.19044.5371",
              "product_id": "11931"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows 10 Version 21H2 for x64-based Systems"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.22621.4751",
            "product": {
              "name": "Windows 11 Version 22H2 for ARM64-based Systems \u003c10.0.22621.4751",
              "product_id": "10"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.22621.4751",
            "product": {
              "name": "Windows 11 Version 22H2 for ARM64-based Systems 10.0.22621.4751",
              "product_id": "12085"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows 11 Version 22H2 for ARM64-based Systems"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.22621.4751",
            "product": {
              "name": "Windows 11 Version 22H2 for x64-based Systems \u003c10.0.22621.4751",
              "product_id": "9"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.22621.4751",
            "product": {
              "name": "Windows 11 Version 22H2 for x64-based Systems 10.0.22621.4751",
              "product_id": "12086"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows 11 Version 22H2 for x64-based Systems"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.19045.5371",
            "product": {
              "name": "Windows 10 Version 22H2 for x64-based Systems \u003c10.0.19045.5371",
              "product_id": "8"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.19045.5371",
            "product": {
              "name": "Windows 10 Version 22H2 for x64-based Systems 10.0.19045.5371",
              "product_id": "12097"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows 10 Version 22H2 for x64-based Systems"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.26100.2894",
            "product": {
              "name": "Windows Server 2025 (Server Core installation) \u003c10.0.26100.2894",
              "product_id": "1"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.26100.2894",
            "product": {
              "name": "Windows Server 2025 (Server Core installation) 10.0.26100.2894",
              "product_id": "12437"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows Server 2025 (Server Core installation)"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.22631.4751",
            "product": {
              "name": "Windows 11 Version 23H2 for ARM64-based Systems \u003c10.0.22631.4751",
              "product_id": "7"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.22631.4751",
            "product": {
              "name": "Windows 11 Version 23H2 for ARM64-based Systems 10.0.22631.4751",
              "product_id": "12242"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows 11 Version 23H2 for ARM64-based Systems"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.22631.4751",
            "product": {
              "name": "Windows 11 Version 23H2 for x64-based Systems \u003c10.0.22631.4751",
              "product_id": "6"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.22631.4751",
            "product": {
              "name": "Windows 11 Version 23H2 for x64-based Systems 10.0.22631.4751",
              "product_id": "12243"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows 11 Version 23H2 for x64-based Systems"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.25398.1369",
            "product": {
              "name": "Windows Server 2022, 23H2 Edition (Server Core installation) \u003c10.0.25398.1369",
              "product_id": "5"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.25398.1369",
            "product": {
              "name": "Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.1369",
              "product_id": "12244"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows Server 2022, 23H2 Edition (Server Core installation)"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.26100.2894",
            "product": {
              "name": "Windows 11 Version 24H2 for ARM64-based Systems \u003c10.0.26100.2894",
              "product_id": "4"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.26100.2894",
            "product": {
              "name": "Windows 11 Version 24H2 for ARM64-based Systems 10.0.26100.2894",
              "product_id": "12389"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows 11 Version 24H2 for ARM64-based Systems"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.26100.2894",
            "product": {
              "name": "Windows 11 Version 24H2 for x64-based Systems \u003c10.0.26100.2894",
              "product_id": "3"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.26100.2894",
            "product": {
              "name": "Windows 11 Version 24H2 for x64-based Systems 10.0.26100.2894",
              "product_id": "12390"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows 11 Version 24H2 for x64-based Systems"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c10.0.26100.2894",
            "product": {
              "name": "Windows Server 2025 \u003c10.0.26100.2894",
              "product_id": "2"
            }
          },
          {
            "category": "product_version",
            "name": "10.0.26100.2894",
            "product": {
              "name": "Windows Server 2025 10.0.26100.2894",
              "product_id": "12436"
            }
          }
        ],
        "category": "product_name",
        "name": "Windows Server 2025"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2025-21335",
      "cwe": {
        "id": "CWE-416",
        "name": "Use After Free"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "An attacker who successfully exploited this vulnerability could gain SYSTEM privileges.",
          "title": "What privileges could be gained by an attacker who successfully exploited this vulnerability?"
        },
        {
          "category": "faq",
          "text": "No, the Hyper-V NT Kernel Integration Virtual Service Provider (VSP) is a component used for communications between the host OS and container-type VMs, such as Windows Sandbox and Microsoft Defender Application Guard (MDAG). It is not in a traditional Hyper-V VM environment. Whereas traditional Hyper-V VMs have a strong boundary between the host and the guest for isolation purposes, container-type VMs like MDAG simulate that they are running on the host.  The Hyper-V NT Kernel Integration VSP driver has functionality that enables this simulation.\nMicrosoft strongly recommends updating to the latest version of Windows to be protected against this vulnerability.\nNo, this is a local elevation of privilege, not any type of guest to host escape.",
          "title": "Does this vulnerability exist in the Hyper-V server?"
        }
      ],
      "product_status": {
        "fixed": [
          "11931",
          "12085",
          "12086",
          "12097",
          "12242",
          "12243",
          "12244",
          "12389",
          "12390",
          "12436",
          "12437"
        ],
        "known_affected": [
          "1",
          "2",
          "3",
          "4",
          "5",
          "6",
          "7",
          "8",
          "9",
          "10",
          "11"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2025-21335 Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21335"
        },
        {
          "category": "self",
          "summary": "CVE-2025-21335 Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2025/msrc_cve-2025-21335.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2025-01-14T00:00:00.000Z",
          "details": "10.0.19044.5371:Security Update:https://support.microsoft.com/help/5049981",
          "product_ids": [
            "11"
          ],
          "url": "https://support.microsoft.com/help/5049981"
        },
        {
          "category": "vendor_fix",
          "date": "2025-01-14T00:00:00.000Z",
          "details": "10.0.22621.4751:Security Update:https://support.microsoft.com/help/5050021",
          "product_ids": [
            "10",
            "9"
          ],
          "url": "https://support.microsoft.com/help/5050021"
        },
        {
          "category": "vendor_fix",
          "date": "2025-01-14T00:00:00.000Z",
          "details": "10.0.19045.5371:Security Update:https://support.microsoft.com/help/5049981",
          "product_ids": [
            "8"
          ],
          "url": "https://support.microsoft.com/help/5049981"
        },
        {
          "category": "vendor_fix",
          "date": "2025-01-14T00:00:00.000Z",
          "details": "10.0.26100.2894:Security Update:https://support.microsoft.com/help/5050009",
          "product_ids": [
            "1",
            "4",
            "3",
            "2"
          ],
          "url": "https://support.microsoft.com/help/5050009"
        },
        {
          "category": "vendor_fix",
          "date": "2025-01-14T00:00:00.000Z",
          "details": "10.0.22631.4751:Security Update:https://support.microsoft.com/help/5050021",
          "product_ids": [
            "7",
            "6"
          ],
          "url": "https://support.microsoft.com/help/5050021"
        },
        {
          "category": "vendor_fix",
          "date": "2025-01-14T00:00:00.000Z",
          "details": "10.0.25398.1369:Security Update:https://support.microsoft.com/help/5049984",
          "product_ids": [
            "5"
          ],
          "url": "https://support.microsoft.com/help/5049984"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 6.8,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1",
            "2",
            "3",
            "4",
            "5",
            "6",
            "7",
            "8",
            "9",
            "10",
            "11"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Elevation of Privilege"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:Yes;Latest Software Release:Exploitation Detected"
        }
      ],
      "title": "Windows Hyper-V NT Kernel Integration VSP Elevation of Privilege Vulnerability"
    }
  ]
}