{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "Kazuma Matsumoto, Security Researcher at GMO Cybersecurity by IERAE, Inc."
        ]
      }
    ],
    "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-2026-20943 Microsoft Office Click-To-Run Remote Code Execution Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20943"
      },
      {
        "category": "self",
        "summary": "CVE-2026-20943 Microsoft Office Click-To-Run Remote Code Execution Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-20943.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 Office Click-To-Run Remote Code Execution Vulnerability",
    "tracking": {
      "current_release_date": "2026-01-20T08:00:00.000Z",
      "generator": {
        "date": "2026-01-20T19:47:59.526Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2026-20943",
      "initial_release_date": "2026-01-13T08:00:00.000Z",
      "revision_history": [
        {
          "date": "2026-01-13T08:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2026-01-20T08:00:00.000Z",
          "legacy_version": "1.1",
          "number": "2",
          "summary": "Corrected the affected product name in the CVE title and in the FAQs. This is an informational change only."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c16.0.10417.20083",
            "product": {
              "name": "Microsoft SharePoint Server 2019 \u003c16.0.10417.20083",
              "product_id": "3"
            }
          },
          {
            "category": "product_version",
            "name": "16.0.10417.20083",
            "product": {
              "name": "Microsoft SharePoint Server 2019 16.0.10417.20083",
              "product_id": "11585"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft SharePoint Server 2019"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c16.0.5535.1000",
            "product": {
              "name": "Microsoft Office 2016 (32-bit edition) \u003c16.0.5535.1000",
              "product_id": "6"
            }
          },
          {
            "category": "product_version",
            "name": "16.0.5535.1000",
            "product": {
              "name": "Microsoft Office 2016 (32-bit edition) 16.0.5535.1000",
              "product_id": "10753"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Office 2016 (32-bit edition)"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c16.0.5535.1000",
            "product": {
              "name": "Microsoft Office 2016 (64-bit edition) \u003c16.0.5535.1000",
              "product_id": "5"
            }
          },
          {
            "category": "product_version",
            "name": "16.0.5535.1000",
            "product": {
              "name": "Microsoft Office 2016 (64-bit edition) 16.0.5535.1000",
              "product_id": "10754"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Office 2016 (64-bit edition)"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c16.0.5535.1001",
            "product": {
              "name": "Microsoft SharePoint Enterprise Server 2016 \u003c16.0.5535.1001",
              "product_id": "4"
            }
          },
          {
            "category": "product_version",
            "name": "16.0.5535.1001",
            "product": {
              "name": "Microsoft SharePoint Enterprise Server 2016 16.0.5535.1001",
              "product_id": "10950"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft SharePoint Enterprise Server 2016"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c16.0.19127.20442",
            "product": {
              "name": "Microsoft SharePoint Server Subscription Edition \u003c16.0.19127.20442",
              "product_id": "2"
            }
          },
          {
            "category": "product_version",
            "name": "16.0.19127.20442",
            "product": {
              "name": "Microsoft SharePoint Server Subscription Edition 16.0.19127.20442",
              "product_id": "11961"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft SharePoint Server Subscription Edition"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c16.0.19426.20170",
            "product": {
              "name": "Microsoft Office Deployment Tool \u003c16.0.19426.20170",
              "product_id": "1"
            }
          },
          {
            "category": "product_version",
            "name": "16.0.19426.20170",
            "product": {
              "name": "Microsoft Office Deployment Tool 16.0.19426.20170",
              "product_id": "20810"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Office Deployment Tool"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-20943",
      "cwe": {
        "id": "CWE-426",
        "name": "Untrusted Search Path"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "Successful exploitation of this vulnerability requires an attacker to prepare the target environment to improve exploit reliability.",
          "title": "According to the CVSS metric, the attack complexity is high (AC:H). What does that mean for this vulnerability?"
        },
        {
          "category": "faq",
          "text": "Customers should download the latest Office Deployment Tool (ODT) and ensure that this version, or any newer version, is used for all future deployments to remain protected against CVE-2026-20943.",
          "title": "Are there additional steps I need to take to be protected from this vulnerability?"
        },
        {
          "category": "faq",
          "text": "A user would need to be tricked into opening a folder that contains a specially crafted file.",
          "title": "According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do?"
        },
        {
          "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": [
          "10753",
          "10754",
          "10950",
          "11585",
          "11961",
          "20810"
        ],
        "known_affected": [
          "1",
          "2",
          "3",
          "4",
          "5",
          "6"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2026-20943 Microsoft Office Click-To-Run Remote Code Execution Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20943"
        },
        {
          "category": "self",
          "summary": "CVE-2026-20943 Microsoft Office Click-To-Run Remote Code Execution Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-20943.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2026-01-13T08:00:00.000Z",
          "details": "16.0.10417.20083:Security Update:https://support.microsoft.com/help/5002825",
          "product_ids": [
            "3"
          ],
          "url": "https://support.microsoft.com/help/5002825"
        },
        {
          "category": "vendor_fix",
          "date": "2026-01-13T08:00:00.000Z",
          "details": "16.0.5535.1000:Security Update:https://support.microsoft.com/help/5002826",
          "product_ids": [
            "6",
            "5"
          ],
          "url": "https://support.microsoft.com/help/5002826"
        },
        {
          "category": "vendor_fix",
          "date": "2026-01-13T08:00:00.000Z",
          "details": "16.0.5535.1001:Security Update:https://support.microsoft.com/help/5002828",
          "product_ids": [
            "4"
          ],
          "url": "https://support.microsoft.com/help/5002828"
        },
        {
          "category": "vendor_fix",
          "date": "2026-01-13T08:00:00.000Z",
          "details": "16.0.19127.20442:Security Update:https://support.microsoft.com/help/5002822",
          "product_ids": [
            "2"
          ],
          "url": "https://support.microsoft.com/help/5002822"
        },
        {
          "category": "vendor_fix",
          "date": "2026-01-13T08:00:00.000Z",
          "details": "16.0.19426.20170:Security Update:https://www.microsoft.com/en-in/download/details.aspx?id=49117\u0026msockid=35f9adb0e74b61392038b90de6fe608c",
          "product_ids": [
            "1"
          ],
          "url": "https://www.microsoft.com/en-in/download/details.aspx?id=49117\u0026msockid=35f9adb0e74b61392038b90de6fe608c"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.0,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "UNCHANGED",
            "temporalScore": 6.1,
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1",
            "2",
            "3",
            "4",
            "5",
            "6"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Remote Code Execution"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely"
        }
      ],
      "title": "Microsoft Office Click-To-Run Remote Code Execution Vulnerability"
    }
  ]
}