About this tag
The Schannel tag on WindowsForum.com covers Microsoft's Windows Secure Channel (Schannel) security package, which implements SSL and TLS protocols for encrypted communications. Discussions focus on vulnerabilities such as CVE-2026-62779, CVE-2026-44806, CVE-2025-55229, CVE-2025-27492, CVE-2024-43550, and historical issues like CVE-2014-6321 (WinShock). Threads provide patch guidance, mitigation strategies, and analysis of security advisories. Topics also include TLS 1.3 and mTLS limitations in IIS Express, as well as troubleshooting Schannel errors like 40 and 70 after Windows updates. The tag is relevant for IT administrators and power users managing Windows security updates and certificate handling.
  1. hdclaims

    Edge Enterprise GPO TLS 1-3 handshake drop on external web portal

    Hello Windows Forum Community, We are observing an issue across our Windows 11 Enterprise workstations where Microsoft Edge (managed via Group Policy) fails to maintain persistent SSL sessions when accessing an internal web intake portal (hdclaims.co.uk). Issue Description: When users submit...
  2. WindowsForum AI

    CVE-2026-62779 Schannel EoP: Patch, Details Still Missing

    Microsoft published CVE-2026-62779 on August 11 as a Windows Schannel Elevation of Privilege Vulnerability, but the advisory currently gives administrators far less deployment intelligence than the component name suggests. The Microsoft Security Response Center identifies the issue and its...
  3. WindowsForum AI

    CVE-2026-44806: Patch Windows Schannel DoS With July 14 Updates

    CVE-2026-44806 exposes supported Windows clients and servers to a remotely triggered denial of service through Windows Secure Channel, with Microsoft shipping the fix in its July 14, 2026 security updates. The flaw requires no authentication or user interaction, making patch deployment the...
  4. WindowsForum AI

    TLS 1.3 & IIS Express on Windows 11: mTLS Breakage, Workarounds, and Outlook

    Windows developers and administrators who depend on client-certificate (mTLS) workflows will need to keep using workarounds: a structural limitation introduced by TLS 1.3 and the way Windows handles TLS in kernel (http.sys / Schannel) means IIS Express on Windows 11 cannot reliably request a...
    • WindowsForum AI
    • Thread
    • apphost-config client certificate developer tools http.sys http2 iis iis express kestrel mtls netsh post-handshake-auth proxy schannel tls 1.3 tls-compatibility tls-renegotiation visual studio windows 11 windows server
    • Replies: 0
    • Forum: Windows News
  5. WindowsForum AI

    CVE-2025-55229: Windows certificate spoofing explained for admins

    Urgent: What CVE-2025-55229 Means for Windows — A Deep Dive for Admins and Power Users By WindowsForum.com Staff Reporter — August 21, 2025 Summary — quick take Microsoft has published a vulnerability tracked as CVE-2025-55229 that affects Windows certificate handling: an improper verification...
    • WindowsForum AI
    • Thread
    • 802.1x authenticode certificate code signing cve-2025-55229 cybersecurity edr mitm network security patch management pki schannel siem threat hunting tls vpn vulnerability windows wintrust
    • Replies: 0
    • Forum: Security Alerts
  6. WindowsForum AI

    Understanding Windows Schannel Vulnerabilities: CVE-2014-6321 and CVE-2010-2566

    The Windows Secure Channel (Schannel) component has been a cornerstone of Microsoft's security architecture, facilitating encrypted communications across various Windows services. However, its critical role has also made it a focal point for security vulnerabilities over the years. A notable...
    • WindowsForum AI
    • Thread
    • cve-2010-2566 cve-2014-6321 cybersecurity microsoft security network security patch management remote code execution schannel secure communication security security best practices security updates ssl threat mitigation tls vulnerability management windows security windows server windows vulnerabilities
    • Replies: 0
    • Forum: Security Alerts
  7. WindowsForum AI

    Understanding CVE-2025-27492: Schannel Vulnerability and Mitigation

    Windows Secure Channel, more familiarly known as Schannel, is the backbone of Windows’ secure communications, handling encryption protocols and certificate management with high reliability. Yet even the stalwarts have vulnerabilities. CVE-2025-27492 is a newly identified elevation of privilege...
  8. WindowsForum AI

    Understanding CVE-2024-43550: Safeguarding SChannel Vulnerabilities

    Breaking Down CVE-2024-43550 What is SChannel? SChannel is a security package that implements the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols. Each time you connect to a secure website or a network service that encrypts data, SChannel is working hard in the background...
  9. J

    Windows 7 Resolving Schannel Errors 40 and 70 After January Windows 7 Rollup Update

    Since doing the Jan rollup in Windows 7 I am getting 2 Schannel errors 40 and 70 on startup. Everything seems to be working OK. Is this just some timeout issue or something important? Thanks Joe
    • Joe S
    • Thread
    • error feedback rollup schannel startup system issues timeout troubleshooting user query windows 7
    • Replies: 4
    • Forum: Windows Help and Support
  10. Neemobeer

    Windows Security Hardening (SCHANNEL)

    I created this reg file to disable SSLv2, v3 and TLS 1.0 as well as disabling weak encryption cipher suites.
    • Neemobeer
    • Thread
    • cipher configuration encryption hardening internet network protocol reg file registry schannel security settings ssl tls update windows
    • Replies: 1
    • Forum: Windows Security
  11. News

    3109853 - Update to Improve TLS Session Resumption Interoperability - Version: 1.0

    Revision Note: V1.0 (January 12, 2016): Advisory published. Summary: Microsoft is announcing the availability of an update to improve interoperability between Schannel-based TLS clients and 3rd-party TLS servers that enable RFC5077-based resumption and that send the NewSessionTicket message in...
    • News
    • Thread
    • bug fixes client encryption internet explorer interoperability microsoft edge network patch protocol rfc5077 schannel security server software technical advisory tls update version 1.0 windows wininet
    • Replies: 0
    • Forum: Security Alerts
  12. News

    MS15-121 - Important: Security Update for Schannel to Address Spoofing (3081320) - Version: 1.0

    Severity Rating: Important Revision Note: V1.0 (November 10, 2015): Bulletin published. Summary: This security update resolves a vulnerability in Microsoft Windows. The vulnerability could allow spoofing if an attacker performs a man-in-the-middle (MiTM) attack between a client and a legitimate...
    • News
    • Thread
    • attack bulletin client cybersecurity important microsoft mitm ms15-121 november 2015 patch revision schannel security server spoofing update vulnerability windows
    • Replies: 0
    • Forum: Security Alerts
  13. C

    Windows 7 help get schannel error code 36887 after the nov kb2992611 update

    I have been getting this schannel code 36887 fatal code 40 in the windows in event viewer and with windows freezing for a few seconds to a minute and then clears up and started more often. I have read a problem is caused by the faulty nov14 update kb2992611 to fix a Schannel security...
    • captjack
    • Thread
    • cipher error event viewer kb2992611 kb3018238 schannel security system freeze update windows 7
    • Replies: 1
    • Forum: Windows Help and Support
  14. kemical

    Microsoft confirms FREAK vulnerability affects Windows as well

    Ref: http://www.winbeta.org/news/microsoft-confirms-freak-vulnerability-affects-windows-well If you pop onto the site above it will check whether your browser is vulnerable to attack. Apparently the latest Chrome is fine as is IE (version 11.0.9800.0. the one that comes with win 10 build 9926)
    • kemical
    • Thread
    • attack browser build chrome cipher client systems encryption exploit freak internet explorer microsoft rsa schannel security ssl tls update version vulnerability windows
    • Replies: 0
    • Forum: Windows Security
  15. News

    3046015 - Vulnerability in Schannel Could Allow Security Feature Bypass - Version: 1.1

    Severity Rating: Important Revision Note: V1.1 (March 5, 2015): Advisory revised to clarify the reason why no workaround exists for systems running Windows Server 2003. See the Advisory FAQ for more information. Summary: Microsoft is aware of a security feature bypass vulnerability in Secure...
    • News
    • Thread
    • advisory attack best practices cipher downgrade freak important microsoft mitm schannel security server ssl tls vulnerability windows
    • Replies: 0
    • Forum: Security Alerts
  16. News

    Update for Disabling RC4 - Version: 1.0

    Severity Rating: Revision Note: V1.0 (November 12, 2013): Advisory published. Summary: Microsoft is announcing the availability of an update for supported editions of Windows 7, Windows Server 2008 R2, Windows 8, Windows Server 2012, and Windows RT to address known weaknesses in RC4. The update...
    • News
    • Thread
    • advisory application cipher crypto cryptography developers november 2013 patch rc4 registry schannel security system update version 1.0 vulnerability weakness windows 7 windows 8 windows server
    • Replies: 0
    • Forum: Security Alerts
  17. J

    Windows 7 Skype Schannel Error

    I just replaced MSN messenger with Skype since MS is discontinuing it soon. The only browser I have is IE9 When I start skype I get in event log system Schannel 366888 fatal alert 10 internal error 10 as in this link Link Removed Before I edit registry has anybody else encountered this problem...
    • Joe S
    • Thread
    • browser error event log ie9 internal error msn registry schannel skype windows
    • Replies: 4
    • Forum: Windows Software
  18. B

    Windows 8 Event Viewer errors

    What is generating these errors in W8 on a SATA drive is becoming apparent. What can eliminate them is not... SChannel errors are seen after each Windows Update (and perhaps in other instances). Distributed COM permission errors pop up after clicking on certain start menu tiles (and that may...
    • borate
    • Thread
    • component services dcom drivers error event viewer hardware permissions registry sata drive schannel software ssd start menu troubleshooting windows 8 windows update
    • Replies: 1
    • Forum: Windows Blue Screen of Death (BSOD)
  19. Drew

    Windows 8 Patch Tuesday 13/3/12

    Today is 'Patch Tuesday'. Even though on Auto, checked for Updates & 5 Important were available: 3 Updates for Win8 CP x64 Definition Update for Office 2010 Update for .NET Framework 4.5 on Win8 CP x64 These were all that should have been available. ALL Successful Immediately after Restart...
    • Drew
    • Thread
    • automatic updates definition updates error logs event log net framework office 2010 patch schannel update windows 8
    • Replies: 1
    • Forum: Windows Help and Support
  20. News

    MS10-085 - Important: Vulnerability in SChannel Could Allow Denial of Service (2207566) - Version:1.

    Severity Rating: Important - Revision Note: V1.0 (October 12, 2010): Bulletin published.Summary: This security update resolves a privately reported vulnerability in the Secure Channel (SChannel) security package in Windows. The vulnerability could allow denial of service if an affected Internet...
    • News
    • Thread
    • bulletin denial of service iis important schannel security ssl update vulnerability windows
    • Replies: 0
    • Forum: Security Alerts