by Kastro
Paper/Archive/CVE-2026-85818

CVE-2026-85818

Microsoft Windows 11 version 23H2 — Windows Schannel Spoofing Vulnerability

EPSS 0.4%CVSS 9.0
critical.is priorityof 100
34
CVSS 9.0 (CNA)9.0 / 10 × 3027.0Not in CISA KEV+300.0EPSS percentile 35.7.357 × 207.1No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.

Affected

ProductAffectedFixed inSource
Windows 11 version 23H210.0.22631.0 – < 10.0.22631.765210.0.22631.7652CNA
Windows 11 Version 23H210.0.22631.0 – < 10.0.22631.765210.0.22631.7652CNA
Windows 11 Version 24H210.0.26100.0 – < 10.0.26100.971110.0.26100.9711CNA
Windows 11 Version 25H210.0.26200.0 – < 10.0.26200.971110.0.26200.9711CNA
Windows 11 version 26H110.0.28000.0 – < 10.0.28000.323110.0.28000.3231CNA
Windows 11 Version 26H210.0.26300.0 – < 10.0.26300.971110.0.26300.9711CNA
Windows Server 202210.0.20348.0 – < 10.0.20348.576110.0.20348.5761CNA
Windows Server 202510.0.26100.0 – < 10.0.26100.3365010.0.26100.33650CNA
Windows Server 2025 (Server Core installation)10.0.26100.0 – < 10.0.26100.3365010.0.26100.33650CNA

Scores by source

microsoft (CNA)9.0CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

patchmsrc.microsoft.com/update-guide/vulnerability/CVE-2026-85818