The update that caused the issues was a Windows security update that landed on October 11 alongside the overall Patch Tuesday releases. It resulted in affected Windows 11 2022 Update devices seeing the error SEC_E_ILLEGAL_MESSAGE within apps that are connected to servers. Microsoft is now sending out KB5018496 preview cumulative update to remedy the problem: “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,” Microsoft reports. “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.” KB5018496 is a preview and is optional, so you will need to grab it manually if you need the fix. To do just that, on your Windows 11 device head to Settings > Windows Update and then “Check for Updates”. Choose the optional KB5018496 from the available updates list.
Updating Older Windows Versions
At the same time, Microsoft is also issuing standalone updates for older Windows versions. These out-of-band releases fix the same problem across the following Windows builds:
Cumulative updates: Windows 11, version 21H2: KB5020387 Windows Server 2022: KB5020436 Windows 10, version 20H2; Windows 10, version 21H1; Windows 10, version 22H1; Windows 10 Enterprise LTSC 2021: KB5020435 Windows 10 Enterprise LTSC 2019; Windows Server 2019: KB5020438 Windows 10 2016 LTSB; Windows Server 2016: KB5020439 Windows 10 2015 LTSB; KB5020440 Standalone Updates: Windows 8.1; Windows Server 2012 R2: KB5020447 Windows Server 2012: KB5020449 Windows 7 SP1; Windows Server 2008 R2 SP1: KB5020448
Tip of the day: Did you know that your data and privacy might be at risk if you run Windows without encryption? A bootable USB with a live-linux distribution is often just enough to gain access to all of your files. If you want to change that, check out our detailed BitLocker guide where we show you how to turn on encryption for your system disk or any other drive you might be using in your computer.
