{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "National Security Agency"
        ]
      }
    ],
    "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-2025-64666 Microsoft Exchange Server Elevation of Privilege Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-64666"
      },
      {
        "category": "self",
        "summary": "CVE-2025-64666 Microsoft Exchange Server Elevation of Privilege Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2025/msrc_cve-2025-64666.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 Exchange Server Elevation of Privilege Vulnerability",
    "tracking": {
      "current_release_date": "2025-12-09T08:00:00.000Z",
      "generator": {
        "date": "2025-12-09T17:55:30.795Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2025-64666",
      "initial_release_date": "2025-12-09T08:00:00.000Z",
      "revision_history": [
        {
          "date": "2025-12-09T08:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c15.02.1748.042",
            "product": {
              "name": "Microsoft Exchange Server 2019 Cumulative Update 15 \u003c15.02.1748.042",
              "product_id": "2"
            }
          },
          {
            "category": "product_version",
            "name": "15.02.1748.042",
            "product": {
              "name": "Microsoft Exchange Server 2019 Cumulative Update 15 15.02.1748.042",
              "product_id": "12502"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Exchange Server 2019 Cumulative Update 15"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c15.01.2507.063",
            "product": {
              "name": "Microsoft Exchange Server 2016 Cumulative Update 23 \u003c15.01.2507.063",
              "product_id": "4"
            }
          },
          {
            "category": "product_version",
            "name": "15.01.2507.063",
            "product": {
              "name": "Microsoft Exchange Server 2016 Cumulative Update 23 15.01.2507.063",
              "product_id": "12039"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Exchange Server 2016 Cumulative Update 23"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c15.02.2562.035",
            "product": {
              "name": "Microsoft Exchange Server Subscription Edition RTM \u003c15.02.2562.035",
              "product_id": "1"
            }
          },
          {
            "category": "product_version",
            "name": "15.02.2562.035",
            "product": {
              "name": "Microsoft Exchange Server Subscription Edition RTM 15.02.2562.035",
              "product_id": "16792"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Exchange Server Subscription Edition RTM"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c15.02.1544.037",
            "product": {
              "name": "Microsoft Exchange Server 2019 Cumulative Update 14 \u003c15.02.1544.037",
              "product_id": "3"
            }
          },
          {
            "category": "product_version",
            "name": "15.02.1544.037",
            "product": {
              "name": "Microsoft Exchange Server 2019 Cumulative Update 14 15.02.1544.037",
              "product_id": "12293"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Exchange Server 2019 Cumulative Update 14"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2025-64666",
      "cwe": {
        "id": "CWE-20",
        "name": "Improper Input Validation"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "Successful exploitation of this vulnerability requires an attacker to take additional actions prior to exploitation to prepare the target environment.",
          "title": "According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?"
        },
        {
          "category": "faq",
          "text": "For Exchange Server 2016 and 2019, update links are not provided because these versions are out of support and security updates are only available through the Extended Security Update (ESU) program.\nCustomers enrolled in ESU can access the December 2025 and future updates, while those not enrolled should migrate to Exchange Server Subscription Edition (SE) to continue receiving security updates. If you have purchased ESU and need assistance accessing updates, contact Microsoft at **ExchangeandSfBServerESUInquiry@service.microsoft.com. **\nFor more details, see the official blog post.",
          "title": "Why are update links missing for some Exchange products?"
        },
        {
          "category": "faq",
          "text": "An attacker who successfully exploited this vulnerability could gain administrator privileges.",
          "title": "What privileges could be gained by an attacker who successfully exploited the vulnerability?"
        }
      ],
      "product_status": {
        "fixed": [
          "12039",
          "12293",
          "12502",
          "16792"
        ],
        "known_affected": [
          "1",
          "2",
          "3",
          "4"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2025-64666 Microsoft Exchange Server Elevation of Privilege Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-64666"
        },
        {
          "category": "self",
          "summary": "CVE-2025-64666 Microsoft Exchange Server Elevation of Privilege Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2025/msrc_cve-2025-64666.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2025-12-09T08:00:00.000Z",
          "details": "15.02.1748.042:Security Update:https://support.microsoft.com/help/5071875",
          "product_ids": [
            "2"
          ],
          "url": "https://support.microsoft.com/help/5071875"
        },
        {
          "category": "vendor_fix",
          "date": "2025-12-09T08:00:00.000Z",
          "details": "15.01.2507.063:Security Update:https://support.microsoft.com/help/5071873",
          "product_ids": [
            "4"
          ],
          "url": "https://support.microsoft.com/help/5071873"
        },
        {
          "category": "vendor_fix",
          "date": "2025-12-09T08:00:00.000Z",
          "details": "15.02.2562.035:Security Update:https://support.microsoft.com/help/5071876",
          "product_ids": [
            "1"
          ],
          "url": "https://support.microsoft.com/help/5071876"
        },
        {
          "category": "vendor_fix",
          "date": "2025-12-09T08:00:00.000Z",
          "details": "15.02.1544.037:Security Update:https://support.microsoft.com/help/5071874",
          "product_ids": [
            "3"
          ],
          "url": "https://support.microsoft.com/help/5071874"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 6.5,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/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"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Elevation of Privilege"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely"
        }
      ],
      "title": "Microsoft Exchange Server Elevation of Privilege Vulnerability"
    }
  ]
}