CVE-2026-85818

Published: Oct 13, 2026Modified: Oct 16, 2026

9.0

Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Exploitability: 2.2 / Impact: 6.0

Source: secure@microsoft.com (Secondary)

Description

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

Affected (12)

Products: Microsoft: Windows 11 23h2, Windows 11 24h2, Windows 11 25h2, Windows 11 26h1, Windows 11 26h2, Windows Server 2022, Windows Server 2025

7 products

Windows 11 23h2

Windows 11 24h2

Windows 11 25h2

Windows 11 26h1

Windows 11 26h2

Windows Server 2022

Windows Server 2025

Configuration A

12 vulnerable

Vulnerable Software	Affected Versions
Microsoft Windows 11 23h2	version < 10.0.22631.7652
Microsoft Windows 11 23h2	version < 10.0.22631.7652
Microsoft Windows 11 24h2	version < 10.0.26100.9711
Microsoft Windows 11 24h2	version < 10.0.26100.9711
Microsoft Windows 11 25h2	version < 10.0.26200.9711
Microsoft Windows 11 25h2	version < 10.0.26200.9711
Microsoft Windows 11 26h1	version < 10.0.28000.3231
Microsoft Windows 11 26h1	version < 10.0.28000.3231
Microsoft Windows 11 26h2	version < 10.0.26300.9711
Microsoft Windows 11 26h2	version < 10.0.26300.9711
Microsoft Windows Server 2022	version < 10.0.20348.5761
Microsoft Windows Server 2025	version < 10.0.26100.33650

Related CWEs

Improper Verification of Cryptographic Signature

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85818

Source: secure@microsoft.com

Vendor AdvisoryPatch

Timeline

No history available yet.