Windows 10 out-of-band update KB5020435 fixes connectivity issues
Microsoft released an out-of-band update for Windows 10 on October 17th, 2022. The update addresses connectivity issues in Windows 10 version 21H2, 21H2 and 20H2.
The out-of-band update is already available. Windows administrators may run a manual check for updates using the Settings application to download and install the update on devices.
Microsoft describes the issue in the following way:
We address an issue that might affect some types of Secure Sockets Layer (SSL) and Transport Layer Security (TLS) connections. These connections might have handshake failures. For developers, the affected connections are likely to receive one or more records followed by a partial record with a size of less than 5 bytes within a single input buffer. If the connection fails, your app will receive the error, “SEC_E_ILLEGAL_MESSAGE”.
According to the description, SSL and TSL connections may fail on affected systems. It is unclear if all programs running on Windows are affected, or only select programs and services. Users may notice connection errors when they encounter the issue.
Installation of the update may resolve the issue. Another option that administrators have is to download the update package from Microsoft's Update Catalog website. There, it is available for all editions of Windows 10 version 20H2, 21H1 and 21H2 that Microsoft supports.
A click on the download button saves the update file to the local system. The packages have a size between 352 megabytes and 704 megabytes.
Please note that manual installation of the update requires that the latest cumulative updates or servicing stack updates are installed on the machines. Microsoft links to these on the following support pages:
All Home editions of Windows 10 version 20H2 reached end of servicing in August 2022. Only Enterprise and Education editions continue to be supported. Support will run out on December 13, 2022, the last Windows Patch Day of the year 2022.
Now You: did you notice connectivity issues on Windows 10 devices recently?
“The out-of-band update is already available.”
…in the Windows Update Catalog.
“Windows administrators may run a manual check for updates using the Settings application to download and install the update on devices.”
No, the KB5020435 article explicitely says it can only be downloaded from the Update Catalog site…
So go the MS Update Catalog:
W10 is a must have for working purposes. Even its updates has become stabler and faster thsn the W11 ones. Thanks for the article!
Something completely different.
Today I could update to Windows 10 pro. version 22H2 (o.s. build 19045.2130).
The question is: I am correct to assume that the KB5020435 patch is already installed in the 22H2 update?
@Paul(us) it’s probably not installed in 22H2, because if you follow the above MS Update Catalog link you will find the patch is also available for 22H2.
@ George, not according to Microsoft –
And still can’t find anything mentioning that the SSL and TLS handshake connection failures issues are fixed in Win.10 22H2.