{"id":"CVE-2026-23666","revision":"67dbcad1289b47e9b2b1e057ffac9829","records":[{"revision":"67dbcad1289b47e9b2b1e057ffac9829","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-23666","aliases":[],"title":".NET Framework Denial of Service Vulnerability","description":"Improper input validation in .NET Framework allows an unauthorized attacker to deny service over a network.","state":0,"publishedAt":"2026-04-14T16:57:53.069+00:00","modifiedAt":"2026-10-15T15:53:06.154+00:00","affected":[{"ecosystem":"Vendor product","name":"Microsoft .NET Framework 3.5","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"vendor\": \"Microsoft\",\n \"product\": \"Microsoft .NET Framework 3.5\",\n \"platforms\": [\n \"Windows Server 2012\",\n \"Windows Server 2012 (Server Core installation)\",\n \"Windows Server 2012 R2\",\n \"Windows Server 2012 R2 (Server Core installation)\"\n ],\n \"versions\": [\n {\n \"version\": \"3.5.0\",\n \"lessThan\": \"2.0.50727.8982 & 3.0.30729.8976\",\n \"versionType\": \"custom\",\n \"status\": \"affected\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Microsoft .NET Framework 3.5 AND 4.7.2","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"vendor\": \"Microsoft\",\n \"product\": \"Microsoft .NET Framework 3.5 AND 4.7.2\",\n \"platforms\": [\n \"Windows 10 Version 1809 for 32-bit Systems\",\n \"Windows 10 Version 1809 for ARM64-based Systems\",\n \"Windows 10 Version 1809 for x64-based Systems\"\n ],\n \"versions\": [\n {\n \"version\": \"4.7.0\",\n \"lessThan\": \"2.0.50727.9068 & 3.0.30729.9065 & 4.7.4141.0\",\n \"versionType\": \"custom\",\n \"status\": \"affected\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Microsoft .NET Framework 3.5 AND 4.8","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"vendor\": \"Microsoft\",\n \"product\": \"Microsoft .NET Framework 3.5 AND 4.8\",\n \"platforms\": [\n \"Windows 10 Version 1809 for 32-bit Systems\",\n \"Windows 10 Version 1809 for ARM64-based Systems\",\n \"Windows 10 Version 1809 for x64-based Systems\",\n \"Windows 10 Version 21H2 for 32-bit Systems\",\n \"Windows 10 Version 21H2 for ARM64-based Systems\",\n \"Windows 10 Version 21H2 for x64-based Systems\",\n \"Windows 10 Version 22H2 for 32-bit Systems\",\n \"Windows 10 Version 22H2 for ARM64-based Systems\",\n \"Windows 10 Version 22H2 for x64-based Systems\",\n \"Windows Server 2022\",\n \"Windows Server 2022 (Server Core installation)\"\n ],\n \"versions\": [\n {\n \"version\": \"4.8.0\",\n \"lessThan\": \"2.0.50727.9068 & 3.0.30729.9065 & 4.8.4801.0\",\n \"versionType\": \"custom\",\n \"status\": \"affected\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Microsoft .NET Framework 3.5 AND 4.8.1","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"vendor\": \"Microsoft\",\n \"product\": \"Microsoft .NET Framework 3.5 AND 4.8.1\",\n \"platforms\": [\n \"Windows 10 Version 21H2 for 32-bit Systems\",\n \"Windows 10 Version 21H2 for ARM64-based Systems\",\n \"Windows 10 Version 21H2 for x64-based Systems\",\n \"Windows 10 Version 22H2 for 32-bit Systems\",\n \"Windows 10 Version 22H2 for ARM64-based Systems\",\n \"Windows 10 Version 22H2 for x64-based Systems\",\n \"Windows 11 Version 22H2 for ARM64-based Systems\",\n \"Windows 11 Version 22H2 for x64-based Systems\",\n \"Windows 11 Version 23H2 for ARM64-based Systems\",\n \"Windows 11 Version 23H2 for x64-based Systems\",\n \"Windows 11 Version 24H2 for ARM64-based Systems\",\n \"Windows 11 Version 24H2 for x64-based Systems\",\n \"Windows 11 Version 25H2 for ARM64-based Systems\",\n \"Windows 11 Version 25H2 for x64-based Systems\",\n \"Windows 11 Version 26H1 for ARM64-based Systems\",\n \"Windows 11 version 26H1 for x64-based Systems\",\n \"Windows Server 2022\",\n \"Windows Server 2022 (Server Core installation)\",\n \"Windows Server 2022, 23H2 Edition (Server Core installation)\",\n \"Windows Server 2025\",\n \"Windows Server 2025 (Server Core installation)\"\n ],\n \"versions\": [\n {\n \"version\": \"4.8.1\",\n \"lessThan\": \"2.0.50727.9181 & 3.0.30729.9165 & 4.8.9332.0\",\n \"versionType\": \"custom\",\n \"status\": \"affected\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"vendor\": \"Microsoft\",\n \"product\": \"Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2\",\n \"platforms\": [\n \"Windows Server 2012\",\n \"Windows Server 2012 (Server Core installation)\",\n \"Windows Server 2012 R2\",\n \"Windows Server 2012 R2 (Server Core installation)\"\n ],\n \"versions\": [\n {\n \"version\": \"4.7.0\",\n \"lessThan\": \"4.8.4801.0\",\n \"versionType\": \"custom\",\n \"status\": \"affected\"\n }\n ]\n }"},{"ecosystem":"Vendor product","name":"Microsoft .NET Framework 4.8","ranges":[],"versions":[],"rawVersionEvidence":"{\n \"vendor\": \"Microsoft\",\n \"product\": \"Microsoft .NET Framework 4.8\",\n \"platforms\": [\n \"Windows 10 Version 1607 for 32-bit Systems\",\n \"Windows 10 Version 1607 for x64-based Systems\",\n \"Windows Server 2012\",\n \"Windows Server 2012 (Server Core installation)\",\n \"Windows Server 2012 R2\",\n \"Windows Server 2012 R2 (Server Core installation)\"\n ],\n \"versions\": [\n {\n \"version\": \"4.8.0\",\n \"lessThan\": \"4.8.4801.0\",\n \"versionType\": \"custom\",\n \"status\": \"affected\"\n }\n ]\n }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:P/RL:O/RC:C","score":7.5,"severity":"HIGH"}],"references":["https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23666"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-23666","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-23666","identifiers":["CVE-2026-23666"]},"retained":false,"historicalAffected":[]}],"coverage":[]}