{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "Ethan Walker"
        ]
      },
      {
        "names": [
          "P1hcn"
        ]
      }
    ],
    "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-2026-63523 Skype for Business Spoofing Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63523"
      },
      {
        "category": "self",
        "summary": "CVE-2026-63523 Skype for Business Spoofing Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-63523.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": "Skype for Business Spoofing Vulnerability",
    "tracking": {
      "current_release_date": "2026-09-08T07:00:00.000Z",
      "generator": {
        "date": "2026-10-16T15:07:51.260Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-63523",
      "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": "<6.0.9319.885",
                "product": {
                  "name": "Skype for Business Server 2015 CU13 <6.0.9319.885",
                  "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": "<7.0.2046.879",
                "product": {
                  "name": "Skype for Business Server Subscription Edition CU1 <7.0.2046.879",
                  "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": "<7.0.2046.569",
                "product": {
                  "name": "Skype for Business Server 2019 CU8 <7.0.2046.569",
                  "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-2026-63523",
      "cwe": {
        "id": "CWE-79",
        "name": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "Integrity is impacted as XSS allows an attacker to add their malicious script to fetch victim's sensitive info or to change DOM execution.",
          "title": "According to the CVSS metrics, successful exploitation of this vulnerability could lead to some loss of integrity (I:L)? What does that mean for this vulnerability?"
        },
        {
          "category": "faq",
          "text": "Limited information from the victim's browser associated with the vulnerable URL can be sent to the attacker by the malicious code.",
          "title": "According to the CVSS metrics, successful exploitation of this vulnerability could lead to some loss of confidentiality (C:L)? What does that mean for this vulnerability?"
        },
        {
          "category": "faq",
          "text": "An attacker would have to send the victim a malicious URL that the victim would have to execute.",
          "title": "According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?"
        }
      ],
      "product_status": {
        "fixed": [
          "12224",
          "21728",
          "21729"
        ],
        "known_affected": [
          "1",
          "2",
          "3"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-63523 Skype for Business Spoofing Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-63523"
        },
        {
          "category": "self",
          "summary": "CVE-2026-63523 Skype for Business Spoofing Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-63523.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": "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"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Spoofing"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely"
        }
      ],
      "title": "Skype for Business Spoofing Vulnerability"
    }
  ]
}