{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "Ron Ben Yizhak with \u003ca href=\"https://www.safebreach.com/\"\u003eSafeBreach\u003c/a\u003e"
        ]
      }
    ],
    "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-2026-45459 Microsoft Excel Security Feature Bypass Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45459"
      },
      {
        "category": "self",
        "summary": "CVE-2026-45459 Microsoft Excel Security Feature Bypass Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-45459.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 Excel Security Feature Bypass Vulnerability",
    "tracking": {
      "current_release_date": "2026-06-09T07:00:00.000Z",
      "generator": {
        "date": "2026-06-09T17:04:14.775Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-45459",
      "initial_release_date": "2026-06-09T07:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-06-09T07:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003chttps://aka.ms/OfficeSecurityReleases",
            "product": {
              "name": "Microsoft 365 Apps for Enterprise for 32-bit Systems \u003chttps://aka.ms/OfficeSecurityReleases",
              "product_id": "7"
            }
          },
          {
            "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": "\u003chttps://aka.ms/OfficeSecurityReleases",
            "product": {
              "name": "Microsoft 365 Apps for Enterprise for 64-bit Systems \u003chttps://aka.ms/OfficeSecurityReleases",
              "product_id": "6"
            }
          },
          {
            "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": "\u003chttps://aka.ms/OfficeSecurityReleases",
            "product": {
              "name": "Microsoft Office LTSC 2024 for 32-bit editions \u003chttps://aka.ms/OfficeSecurityReleases",
              "product_id": "4"
            }
          },
          {
            "category": "product_version",
            "name": "https://aka.ms/OfficeSecurityReleases",
            "product": {
              "name": "Microsoft Office LTSC 2024 for 32-bit editions https://aka.ms/OfficeSecurityReleases",
              "product_id": "12420"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Office LTSC 2024 for 32-bit editions"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003chttps://aka.ms/OfficeSecurityReleases",
            "product": {
              "name": "Microsoft Office LTSC 2024 for 64-bit editions \u003chttps://aka.ms/OfficeSecurityReleases",
              "product_id": "3"
            }
          },
          {
            "category": "product_version",
            "name": "https://aka.ms/OfficeSecurityReleases",
            "product": {
              "name": "Microsoft Office LTSC 2024 for 64-bit editions https://aka.ms/OfficeSecurityReleases",
              "product_id": "12421"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Office LTSC 2024 for 64-bit editions"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-45459",
      "cwe": {
        "id": "CWE-693",
        "name": "Protection Mechanism Failure"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "An attacker who successfully exploited the vulnerability could view some sensitive information (Confidentiality) but not all resources within the impacted component may be divulged to the attacker. The attacker cannot make changes to disclosed information (Integrity) or limit access to the resource (Availability).",
          "title": "According to the CVSS metrics, successful exploitation of this vulnerability could lead to some loss of confidentiality (C:L),but lead to no loss of availability (A:N) and integrity (I:N)? What does that mean for this vulnerability?"
        },
        {
          "category": "faq",
          "text": "An attacker must send a user a malicious Office file and convince them to open it.",
          "title": "According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?"
        },
        {
          "category": "faq",
          "text": "Successful exploitation of this vulnerability would allow an attacker to bypass the Office Protected View and open in editing mode rather than protected mode.",
          "title": "What kind of security feature could be bypassed by successfully exploiting this vulnerability?"
        },
        {
          "category": "faq",
          "text": "The security update for Microsoft Office LTSC for Mac 2021, 2024 and Microsoft 365 for Mac are not immediately available. The updates will be released as soon as possible, and when they are available, customers will be notified via a revision to this CVE information.",
          "title": "Are the updates for the Microsoft Office LTSC and Microsoft 365 for Mac currently available?"
        },
        {
          "category": "faq",
          "text": "No, the Preview Pane is not an attack vector.",
          "title": "Is the Preview Pane an attack vector for this vulnerability?"
        }
      ],
      "product_status": {
        "fixed": [
          "11762",
          "11763",
          "11951",
          "12420",
          "12421",
          "12440",
          "21368"
        ],
        "known_affected": [
          "1",
          "2",
          "3",
          "4",
          "5",
          "6",
          "7"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-45459 Microsoft Excel Security Feature Bypass Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45459"
        },
        {
          "category": "self",
          "summary": "CVE-2026-45459 Microsoft Excel Security Feature Bypass Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-45459.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-06-09T07:00:00.000Z",
          "details": "https://aka.ms/OfficeSecurityReleases:Security Update:https://docs.microsoft.com/en-us/officeupdates/office365-proplus-security-updates",
          "product_ids": [
            "7",
            "6",
            "4",
            "3"
          ],
          "url": "https://docs.microsoft.com/en-us/officeupdates/office365-proplus-security-updates"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 3.3,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "environmentalsScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 2.9,
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1",
            "2",
            "3",
            "4",
            "5",
            "6",
            "7"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Security Feature Bypass"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely"
        }
      ],
      "title": "Microsoft Excel Security Feature Bypass Vulnerability"
    }
  ]
}