{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-55040",
        "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
        "state": "PUBLISHED",
        "assignerShortName": "microsoft",
        "dateReserved": "2026-06-16T14:13:49.835Z",
        "datePublished": "2026-07-14T17:09:00.641Z",
        "dateUpdated": "2026-09-02T17:57:00.157Z"
    },
    "containers": {
        "cna": {
            "title": "Microsoft SharePoint Server Security Feature Bypass Vulnerability",
            "datePublic": "2026-07-14T14:00:00.000Z",
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:a:microsoft:sharepoint_server_2016:*:*:*:*:enterprise:*:*:*",
                                    "versionStartIncluding": "16.0.0",
                                    "versionEndExcluding": "16.0.5561.1001"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:a:microsoft:sharepoint_server_2019:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "16.0.0",
                                    "versionEndExcluding": "16.0.10417.20175"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:*",
                                    "versionStartIncluding": "16.0.0",
                                    "versionEndExcluding": "16.0.19725.20434"
                                }
                            ]
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Enterprise Server 2016",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.5561.1001",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                },
                {
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Server 2019",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.10417.20175",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                },
                {
                    "vendor": "Microsoft",
                    "product": "Microsoft SharePoint Server Subscription Edition",
                    "platforms": [
                        "x64-based Systems"
                    ],
                    "versions": [
                        {
                            "version": "16.0.0",
                            "lessThan": "16.0.19725.20434",
                            "versionType": "custom",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "descriptions": [
                {
                    "value": "Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.",
                    "lang": "en-US"
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "description": "CWE-1390: Weak Authentication",
                            "lang": "en-US",
                            "type": "CWE",
                            "cweId": "CWE-1390"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
                "shortName": "microsoft",
                "dateUpdated": "2026-09-02T17:57:00.157Z"
            },
            "references": [
                {
                    "name": "Microsoft SharePoint Server Security Feature Bypass Vulnerability",
                    "tags": [
                        "vendor-advisory",
                        "patch"
                    ],
                    "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55040"
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en-US",
                            "value": "GENERAL"
                        }
                    ],
                    "cvssV3_1": {
                        "version": "3.1",
                        "baseSeverity": "CRITICAL",
                        "baseScore": 9.1,
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:U/RL:O/RC:C"
                    }
                }
            ]
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-07-13T00:00:00+00:00",
                                "options": [
                                    {
                                        "Exploitation": "active"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3",
                                "id": "CVE-2026-55040"
                            }
                        }
                    },
                    {
                        "other": {
                            "type": "kev",
                            "content": {
                                "dateAdded": "2026-08-18",
                                "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55040"
                            }
                        }
                    }
                ],
                "references": [
                    {
                        "url": "https://www.rapid7.com/blog/post/ra-microsoft-sharepoint-jwt-token-authentication-bypass-cve-2026-55040/",
                        "tags": [
                            "technical-description"
                        ]
                    },
                    {
                        "url": "https://github.com/sfewer-r7/CVE-2026-55040",
                        "tags": [
                            "exploit"
                        ]
                    },
                    {
                        "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-55040",
                        "tags": [
                            "government-resource"
                        ]
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-08-19T03:55:48.123Z"
                },
                "timeline": [
                    {
                        "time": "2026-08-18T00:00:00.000Z",
                        "lang": "en",
                        "value": "CVE-2026-55040 added to CISA KEV"
                    }
                ]
            }
        ]
    }
}