{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "Michael Maturi with Google"
        ]
      }
    ],
    "aggregate_severity": {
      "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
      "text": "Critical"
    },
    "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-2026-55008 Microsoft Exchange Server Spoofing Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55008"
      },
      {
        "category": "self",
        "summary": "CVE-2026-55008 Microsoft Exchange Server Spoofing Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-55008.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 Spoofing Vulnerability",
    "tracking": {
      "current_release_date": "2026-07-14T07:00:00.000Z",
      "generator": {
        "date": "2026-07-14T20:05:38.277Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-55008",
      "initial_release_date": "2026-07-14T07:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-07-14T07:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c15.01.2507.071",
            "product": {
              "name": "Microsoft Exchange Server 2016 Cumulative Update 23 \u003c15.01.2507.071",
              "product_id": "4"
            }
          },
          {
            "category": "product_version",
            "name": "15.01.2507.071",
            "product": {
              "name": "Microsoft Exchange Server 2016 Cumulative Update 23 15.01.2507.071",
              "product_id": "12039"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Exchange Server 2016 Cumulative Update 23"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c15.02.1544.043",
            "product": {
              "name": "Microsoft Exchange Server 2019 Cumulative Update 14 \u003c15.02.1544.043",
              "product_id": "3"
            }
          },
          {
            "category": "product_version",
            "name": "15.02.1544.043",
            "product": {
              "name": "Microsoft Exchange Server 2019 Cumulative Update 14 15.02.1544.043",
              "product_id": "12293"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Exchange Server 2019 Cumulative Update 14"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c15.02.1748.048",
            "product": {
              "name": "Microsoft Exchange Server 2019 Cumulative Update 15 \u003c15.02.1748.048",
              "product_id": "2"
            }
          },
          {
            "category": "product_version",
            "name": "15.02.1748.048",
            "product": {
              "name": "Microsoft Exchange Server 2019 Cumulative Update 15 15.02.1748.048",
              "product_id": "12502"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Exchange Server 2019 Cumulative Update 15"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c15.02.2562.045",
            "product": {
              "name": "Microsoft Exchange Server Subscription Edition RTM \u003c15.02.2562.045",
              "product_id": "1"
            }
          },
          {
            "category": "product_version",
            "name": "15.02.2562.045",
            "product": {
              "name": "Microsoft Exchange Server Subscription Edition RTM 15.02.2562.045",
              "product_id": "16792"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Exchange Server Subscription Edition RTM"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-55008",
      "cwe": {
        "id": "CWE-79",
        "name": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "An attacker could exploit this issue by sending a specifically crafted malicious email to the user. If the user opens this email, in Outlook Web Access, and certain conditions are met, arbitrary execution of JavaScript would occur in the browser context.",
          "title": "How could an attacker exploit this vulnerability?"
        }
      ],
      "product_status": {
        "fixed": [
          "12039",
          "12293",
          "12502",
          "16792"
        ],
        "known_affected": [
          "1",
          "2",
          "3",
          "4"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-55008 Microsoft Exchange Server Spoofing Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55008"
        },
        {
          "category": "self",
          "summary": "CVE-2026-55008 Microsoft Exchange Server Spoofing Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-55008.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-07-14T07:00:00.000Z",
          "details": "15.01.2507.071:Security Update:https://support.microsoft.com/help/5103215",
          "product_ids": [
            "4"
          ],
          "url": "https://support.microsoft.com/help/5103215"
        },
        {
          "category": "vendor_fix",
          "date": "2026-07-14T07:00:00.000Z",
          "details": "15.02.1544.043:Security Update:https://support.microsoft.com/help/5103214",
          "product_ids": [
            "3"
          ],
          "url": "https://support.microsoft.com/help/5103214"
        },
        {
          "category": "vendor_fix",
          "date": "2026-07-14T07:00:00.000Z",
          "details": "15.02.1748.048:Security Update:https://support.microsoft.com/help/5103213",
          "product_ids": [
            "2"
          ],
          "url": "https://support.microsoft.com/help/5103213"
        },
        {
          "category": "vendor_fix",
          "date": "2026-07-14T07:00:00.000Z",
          "details": "15.02.2562.045:Security Update:https://support.microsoft.com/help/5103212",
          "product_ids": [
            "1"
          ],
          "url": "https://support.microsoft.com/help/5103212"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.6,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "environmentalScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "CHANGED",
            "temporalScore": 8.3,
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1",
            "2",
            "3",
            "4"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Spoofing"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation More Likely"
        }
      ],
      "title": "Microsoft Exchange Server Spoofing Vulnerability"
    }
  ]
}