{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "yhw & txz"
        ]
      }
    ],
    "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-2026-64918 Microsoft Office Spoofing Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64918"
      },
      {
        "category": "self",
        "summary": "CVE-2026-64918 Microsoft Office Spoofing Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-64918.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": "Microsoft Office Spoofing Vulnerability",
    "tracking": {
      "current_release_date": "2026-09-08T07:00:00.000Z",
      "generator": {
        "date": "2026-11-03T01:26:25.658Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-64918",
      "initial_release_date": "2026-09-08T07:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-09-08T07:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "<https://aka.ms/OfficeSecurityReleases",
                "product": {
                  "name": "Microsoft Office 2019 for 32-bit editions <https://aka.ms/OfficeSecurityReleases",
                  "product_id": "4"
                }
              },
              {
                "category": "product_version",
                "name": "https://aka.ms/OfficeSecurityReleases",
                "product": {
                  "name": "Microsoft Office 2019 for 32-bit editions https://aka.ms/OfficeSecurityReleases",
                  "product_id": "11573"
                }
              }
            ],
            "category": "product_name",
            "name": "Microsoft Office 2019 for 32-bit editions"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "<https://aka.ms/OfficeSecurityReleases",
                "product": {
                  "name": "Microsoft Office 2019 for 64-bit editions <https://aka.ms/OfficeSecurityReleases",
                  "product_id": "3"
                }
              },
              {
                "category": "product_version",
                "name": "https://aka.ms/OfficeSecurityReleases",
                "product": {
                  "name": "Microsoft Office 2019 for 64-bit editions https://aka.ms/OfficeSecurityReleases",
                  "product_id": "11574"
                }
              }
            ],
            "category": "product_name",
            "name": "Microsoft Office 2019 for 64-bit editions"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "<https://aka.ms/OfficeSecurityReleases",
                "product": {
                  "name": "Microsoft 365 Apps for Enterprise for 32-bit Systems <https://aka.ms/OfficeSecurityReleases",
                  "product_id": "2"
                }
              },
              {
                "category": "product_version",
                "name": "https://aka.ms/OfficeSecurityReleases",
                "product": {
                  "name": "Microsoft 365 Apps for Enterprise for 32-bit Systems https://aka.ms/OfficeSecurityReleases",
                  "product_id": "11762"
                }
              }
            ],
            "category": "product_name",
            "name": "Microsoft 365 Apps for Enterprise for 32-bit Systems"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "<https://aka.ms/OfficeSecurityReleases",
                "product": {
                  "name": "Microsoft 365 Apps for Enterprise for 64-bit Systems <https://aka.ms/OfficeSecurityReleases",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "https://aka.ms/OfficeSecurityReleases",
                "product": {
                  "name": "Microsoft 365 Apps for Enterprise for 64-bit Systems https://aka.ms/OfficeSecurityReleases",
                  "product_id": "11763"
                }
              }
            ],
            "category": "product_name",
            "name": "Microsoft 365 Apps for Enterprise for 64-bit Systems"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "<16.0.5569.1003",
                "product": {
                  "name": "Microsoft Office 2016 (32-bit edition) <16.0.5569.1003",
                  "product_id": "6"
                }
              },
              {
                "category": "product_version",
                "name": "16.0.5569.1003",
                "product": {
                  "name": "Microsoft Office 2016 (32-bit edition) 16.0.5569.1003",
                  "product_id": "10753"
                }
              }
            ],
            "category": "product_name",
            "name": "Microsoft Office 2016 (32-bit edition)"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "<16.0.5569.1003",
                "product": {
                  "name": "Microsoft Office 2016 (64-bit edition) <16.0.5569.1003",
                  "product_id": "5"
                }
              },
              {
                "category": "product_version",
                "name": "16.0.5569.1003",
                "product": {
                  "name": "Microsoft Office 2016 (64-bit edition) 16.0.5569.1003",
                  "product_id": "10754"
                }
              }
            ],
            "category": "product_name",
            "name": "Microsoft Office 2016 (64-bit edition)"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-64918",
      "cwe": {
        "id": "CWE-522",
        "name": "Insufficiently Protected Credentials"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "A user interacting with the file in multiple ways will cause the NTLM hash to be leaked. A few interactions which trigger this leak include:\nOpening the parent folder in Explorer, Clicking the file (any mouse button), Dragging the file, Deleting the file",
          "title": "According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?"
        }
      ],
      "product_status": {
        "fixed": [
          "10753",
          "10754",
          "11573",
          "11574",
          "11762",
          "11763"
        ],
        "known_affected": [
          "1",
          "2",
          "3",
          "4",
          "5",
          "6"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-64918 Microsoft Office Spoofing Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-64918"
        },
        {
          "category": "self",
          "summary": "CVE-2026-64918 Microsoft Office Spoofing Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-64918.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-09-08T07:00:00.000Z",
          "details": "https://aka.ms/OfficeSecurityReleases:Security Update:https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates",
          "product_ids": [
            "4",
            "3"
          ],
          "url": "https://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates"
        },
        {
          "category": "vendor_fix",
          "date": "2026-09-08T07:00:00.000Z",
          "details": "https://aka.ms/OfficeSecurityReleases:Security Update:https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates",
          "product_ids": [
            "2",
            "1"
          ],
          "url": "https://learn.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates"
        },
        {
          "category": "vendor_fix",
          "date": "2026-09-08T07:00:00.000Z",
          "details": "16.0.5569.1003:Security Update:https://support.microsoft.com/help/5002916",
          "product_ids": [
            "6",
            "5"
          ],
          "url": "https://support.microsoft.com/help/5002916"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 5.7,
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1",
            "2",
            "3",
            "4",
            "5",
            "6"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Spoofing"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely"
        }
      ],
      "title": "Microsoft Office Spoofing Vulnerability"
    }
  ]
}