Microsoft confirms October Patch Tuesday has network issues on Windows 11, Windows 10, more

Last week, Microsoft released its Patch Tuesday of October. It was also the first time the new Windows 11 version 22H2 received its first such security update. The updates were out under KB5018418 on Windows 11 21H2 and KB5018427 on 22H2.

It seems they were not without issues, as Microsoft has confirmed the October Patch Tuesday is causing problems in establishing network connectivity. The company explains that several users have reported Transport Layer Security (TLS)/ SSL protocol handshake failures, which is leading to the failure to establish communication between clients and their servers.

On its Windows health dashboard, the company writes:

Microsoft has received reports that after installing KB5018427, some types of SSL (Secure Sockets Layer) and TLS (Transport Layer Security) connections might have handshake failures. Note for developers: Affected connections are likely to be sending multiple frames within a single input buffer, specifically one or more complete records with a partial record that is less than 5 bytes all sent in a single buffer. When this issue is encountered, your app will receive SEC_E_ILLEGAL_MESSAGE when the connection fails.

Microsoft has also provided a set of steps so that users experiencing the issue can report it using Feedback Hub. The firm says it is looking into the problem:

If you are experiencing issues, please use feedback hub to file a report following the below steps:

1. Launch Feedback Hub by opening the Start menu and typing "Feedback hub", or pressing the Windows key + F
2. Fill in the "Summarize your feedback" and "Explain in more detail" boxes, then click Next.
3. Under the "Choose a category" section, ensure the "Problem" button, "Devices and Drivers" category, and "Print" subcategory are all selected. Click Next.
4. Under the "Find similar feedback" section, select the "Make new bug" radio button and click Next.
5. Under the "Add more details" section, supply any relevant detail (Note this is not critical to addressing your issue).
6. Expand the "Recreate my problem" box and press "Start recording". Reproduce the issue on your device.
7. Press "Stop recording" once finished. Click the "Submit" button.

All Windows versions, including Windows 10 (KB5018410), are affected. Though thankfully, the issue has been resolved with the new KB5020435 out-of-band update. Over on the Windows 11 side, the fix via an out-of-band (OOB) update KB5020387 has been issued for version 21H2. Windows 11 2022 though remains unresolved.