{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-66307", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2026-07-24T18:06:51.294Z", "datePublished": "2026-09-08T18:39:44.434Z", "dateUpdated": "2026-10-14T23:14:57.199Z" }, "containers": { "cna": { "title": "Skype for Business and Lync Denial of Service Vulnerability", "datePublic": "2026-09-08T14:00:00.000Z", "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:a:microsoft:skype_for_business_server_2015:*:cu13:*:*:*:*:*:*", "versionStartIncluding": "9319.0", "versionEndExcluding": "6.0.9319.885" }, { "vulnerable": true, "criteria": "cpe:2.3:a:microsoft:skype_for_business_server_subscription_edition:*:cu1:*:*:*:*:*:*", "versionStartIncluding": "2046.0", "versionEndExcluding": "7.0.2046.879" }, { "vulnerable": true, "criteria": "cpe:2.3:a:microsoft:skype_for_business_server_2019:*:cu8:*:*:*:*:*:*", "versionStartIncluding": "2046.0", "versionEndExcluding": "7.0.2046.569" } ] } ] } ], "affected": [ { "vendor": "Microsoft", "product": "Skype for Business Server 2015 CU13", "platforms": [ "x64-based Systems" ], "versions": [ { "version": "9319.0", "lessThan": "6.0.9319.885", "versionType": "custom", "status": "affected" } ] }, { "vendor": "Microsoft", "product": "Skype for Business Server 2019 CU8", "platforms": [ "x64-based Systems" ], "versions": [ { "version": "2046.0", "lessThan": "7.0.2046.569", "versionType": "custom", "status": "affected" } ] }, { "vendor": "Microsoft", "product": "Skype for Business Server Subscription Edition CU1", "platforms": [ "x64-based Systems" ], "versions": [ { "version": "2046.0", "lessThan": "7.0.2046.879", "versionType": "custom", "status": "affected" } ] } ], "descriptions": [ { "value": "Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network.", "lang": "en-US" } ], "problemTypes": [ { "descriptions": [ { "description": "CWE-191: Integer Underflow (Wrap or Wraparound)", "lang": "en-US", "type": "CWE", "cweId": "CWE-191" } ] } ], "providerMetadata": { "orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-10-14T23:14:57.199Z" }, "references": [ { "name": "Skype for Business and Lync Denial of Service Vulnerability", "tags": [ "vendor-advisory", "patch" ], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66307" } ], "metrics": [ { "format": "CVSS", "scenarios": [ { "lang": "en-US", "value": "GENERAL" } ], "cvssV3_1": { "version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.5, "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C" } } ] }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-09-08T19:14:13.483335Z", "id": "CVE-2026-66307", "options": [ { "Exploitation": "none" }, { "Automatable": "yes" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-08T19:17:17.096Z" } } ] } }