CVE-2026-85818
Windows Schannel Spoofing Vulnerability
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Windows Schannel Spoofing Vulnerability
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.
- Record
CVE-2026-85818- CVSS 3.1
- 9.0 Critical
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 - Weakness
- CWE-347
- Updated
- 2026-11-10
EUVDEUVD-2026-99528
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.
- Record
EUVD-2026-99528- CVSS 3.1
- 9.0 Critical
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 - Updated
- 2026-11-10
GitHub AdvisoriesGHSA-7j3q-9qpw-gwc7
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized...
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.
- Record
GHSA-7j3q-9qpw-gwc7- CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-347
- Updated
- 2026-11-02
NVD
Improper verification of cryptographic signature in Windows Schannel allows an unauthorized attacker to perform spoofing over a network.
- Record
CVE-2026-85818- CVSS 3.1
- 9.0 Critical
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-347
- Updated
- 2026-11-02
Affected products
- microsoft windows 11 version 23h2
- microsoft windows 11 version 24h2
- microsoft windows 11 version 25h2
- microsoft windows 11 version 26h1
- microsoft windows 11 version 26h2
- microsoft windows server 2022
- microsoft windows server 2025
- microsoft windows server 2025 (server core installation)
- microsoft windows 11 23h2
- microsoft windows 11 24h2
- microsoft windows 11 25h2
- microsoft windows 11 26h1
Show 1 moreShow less
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | CVE List | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-85818 is a critical vulnerability (CVSS 9.0) in Microsoft Windows 11 Version 23h2, published October 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.41%, the 36th percentile. No source names a fixed version.