CVE-2026-85818

Windows Schannel Spoofing Vulnerability

Published Oct 13, 2026 CVSS 3.1 · 9 Critical EPSS < 1% KEV · Not listed
Description
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Microsoft windows Server 2025 (server Core Installation)
Vendors & Products Microsoft windows Server 2025 (server Core Installation)
Type Values Removed Values Added
First Time appeared Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows 11 25h2
Microsoft windows 11 26h1
Microsoft windows 11 26h2
CPEs cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*
Vendors & Products Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows 11 25h2
Microsoft windows 11 26h1
Microsoft windows 11 26h2
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.
Title Windows Schannel Spoofing Vulnerability
First Time appeared Microsoft
Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows 11 25h2
Microsoft windows 11 26h1
Microsoft windows 11 Version 26h2 For Arm64-based Systems
Microsoft windows Server 2022
Microsoft windows Server 2025
Weaknesses CWE-347
CPEs cpe:2.3:a:microsoft:windows_11_version_26h2_for_arm64-based_systems:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_23H2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
Vendors & Products Microsoft
Microsoft windows 11 23h2
Microsoft windows 11 24h2
Microsoft windows 11 25h2
Microsoft windows 11 26h1
Microsoft windows 11 Version 26h2 For Arm64-based Systems
Microsoft windows Server 2022
Microsoft windows Server 2025
References
Metrics cvssV3_1

{'score': 9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C'}