KB5020387 Windows 11, 21H2 Out of Band Update

Microsoft has released an out-of-band update to Windows 11 21H2 (KB number KB5020387) to the public. This update includes the following changes:

  • This article addresses an issue that could affect certain types of Secure Sockets Layer and Transport Layer Security connections. These connections could experience handshake problems. Developers will likely receive one or more records from affected connections, followed by a partial file with a smaller size than 5 bytes in a single input buffer. If the connection fails, your app will receive the error, “SEC_E_ILLEGAL_MESSAGE”.

Your build number will increase to 22000.1100 after installing the update KB5020387.

Download: x64-KB5020387
Download: arm-KB5020387

Christopher Woodill

About ME

Enterprise technology leader for the past 15+ years…certified PMP, Six Sigma Black Belt and TOGAF Enterprise Architect. I collaborate with companies to help align their strategic objectives with concrete implementable technology strategies. I am Vice President, Enterprise Solutions for Klick Health.

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