{
  "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-2026-66307 Skype for Business and Lync Denial of Service Vulnerability - VEX",
        "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-66307.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": "Skype for Business and Lync Denial of Service Vulnerability",
    "tracking": {
      "current_release_date": "2026-09-08T07:00:00.000Z",
      "generator": {
        "date": "2026-10-01T22:52:25.157Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-66307",
      "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": "\u003c6.0.9319.885",
                "product": {
                  "name": "Skype for Business Server 2015 CU13 \u003c6.0.9319.885",
                  "product_id": "3"
                }
              },
              {
                "category": "product_version",
                "name": "6.0.9319.885",
                "product": {
                  "name": "Skype for Business Server 2015 CU13 6.0.9319.885",
                  "product_id": "12224"
                }
              }
            ],
            "category": "product_name",
            "name": "Skype for Business Server 2015 CU13"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c7.0.2046.879",
                "product": {
                  "name": "Skype for Business Server Subscription Edition CU1 \u003c7.0.2046.879",
                  "product_id": "1"
                }
              },
              {
                "category": "product_version",
                "name": "7.0.2046.879",
                "product": {
                  "name": "Skype for Business Server Subscription Edition CU1 7.0.2046.879",
                  "product_id": "21729"
                }
              }
            ],
            "category": "product_name",
            "name": "Skype for Business Server Subscription Edition CU1"
          },
          {
            "branches": [
              {
                "category": "product_version_range",
                "name": "\u003c7.0.2046.569",
                "product": {
                  "name": "Skype for Business Server 2019 CU8 \u003c7.0.2046.569",
                  "product_id": "2"
                }
              },
              {
                "category": "product_version",
                "name": "7.0.2046.569",
                "product": {
                  "name": "Skype for Business Server 2019 CU8 7.0.2046.569",
                  "product_id": "21728"
                }
              }
            ],
            "category": "product_name",
            "name": "Skype for Business Server 2019 CU8"
          }
        ],
        "category": "vendor",
        "name": "Microsoft"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-66307",
      "cwe": {
        "id": "CWE-191",
        "name": "Integer Underflow (Wrap or Wraparound)"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        }
      ],
      "product_status": {
        "fixed": [
          "12224",
          "21729",
          "21728"
        ],
        "known_affected": [
          "3",
          "1",
          "2"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-66307 Skype for Business and Lync Denial of Service Vulnerability - VEX",
          "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-66307.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-09-08T07:00:00.000Z",
          "details": "6.0.9319.885:Security Update:https://support.microsoft.com/help/5123301",
          "product_ids": [
            "3"
          ],
          "url": "https://support.microsoft.com/help/5123301"
        },
        {
          "category": "vendor_fix",
          "date": "2026-09-08T07:00:00.000Z",
          "details": "7.0.2046.879:Security Update:https://support.microsoft.com/help/5123287",
          "product_ids": [
            "1"
          ],
          "url": "https://support.microsoft.com/help/5123287"
        },
        {
          "category": "vendor_fix",
          "date": "2026-09-08T07:00:00.000Z",
          "details": "7.0.2046.569:Security Update:https://support.microsoft.com/help/5123300",
          "product_ids": [
            "2"
          ],
          "url": "https://support.microsoft.com/help/5123300"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 6.5,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1",
            "2",
            "3"
          ]
        }
      ],
      "title": "Skype for Business and Lync Denial of Service Vulnerability"
    }
  ]
}