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{"affected": [{"affectedData": [{"platforms": ["x64-based Systems"], "product": "Skype for Business Server 2015 CU13", "vendor": "Microsoft", "versions": [{"lessThan": "6.0.9319.885", "status": "affected", "version": "9319.0", "versionType": "custom"}]}, {"platforms": ["x64-based Systems"], "product": "Skype for Business Server 2019 CU8", "vendor": "Microsoft", "versions": [{"lessThan": "7.0.2046.569", "status": "affected", "version": "2046.0", "versionType": "custom"}]}, {"platforms": ["x64-based Systems"], "product": "Skype for Business Server Subscription Edition CU1", "vendor": "Microsoft", "versions": [{"lessThan": "7.0.2046.879", "status": "affected", "version": "2046.0", "versionType": "custom"}]}], "source": "secure@microsoft.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Integer underflow (wrap or wraparound) in Skype for Business allows an unauthorized attacker to deny service over a network."}], "id": "CVE-2026-66307", "lastModified": "2026-09-08T19:22:18.470", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "secure@microsoft.com", "type": "Primary"}]}, "published": "2026-09-08T19:18:08.327", "references": [{"source": "secure@microsoft.com", "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-66307"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-191"}], "source": "secure@microsoft.com", "type": "Primary"}]}

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