{ "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": "2026-08-20T17:05:18.721Z" }, "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": "2026-08-20T17:05:18.721Z" }, "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" } ] } ] } }