{"id":"CVE-2026-85818","published":"2026-10-13T19:21:06.667","lastModified":"2026-10-16T19:58:02.273","description":"Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.","cvssScore":9,"cvssSeverity":"CRITICAL","cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H","cwes":["CWE-347"],"vendors":["microsoft"],"products":["windows 11 23h2","windows 11 24h2","windows 11 25h2","windows 11 26h1","windows 11 26h2","windows server 2022","windows server 2025"],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85818","tags":["Vendor Advisory","Patch"]}],"exploitRefs":[],"hasPoc":false,"ai":{"summary":"This vulnerability allows attackers to bypass cryptographic signature verification in Windows Schannel, enabling them to spoof network communications and potentially impersonate legitimate services or users. The flaw is critical because it undermines the core security of encrypted network connections.","exploitability":"Exploitation requires a network-based attack with minimal preconditions, as the vulnerability affects the TLS/SSL handshake process where signature verification occurs.","blast_radius":"If exploited, this could allow attackers to impersonate any service or user on networks using Windows Schannel, potentially leading to widespread man-in-the-middle attacks across enterprise networks.","remediation":"Apply the latest Windows updates that include the fix for CVE-2026-85818, specifically the patches released in the October 2026 security update bulletin.","detection":"No reliable host or network indicator is derivable from the published description.","tags":["tls","mitm","network-security"],"model":"garnet-coder","analyzedAt":"2026-10-16T08:50:30.329Z"}}