Microsoft Releases Fix for TLS/SLS Connection Issues on Windows PCs

Windows 11

Microsoft is rolling out an out-of-band update to address an issue that causes Transport Layer Security (TLS)/ Secure Sockets Layer (SSL) handshake failures on Windows PCs. The company has acknowledged on the Windows release health dashboard that the October Patch Tuesday updates trigger network connectivity problems on various supported versions of Windows.

“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”,” the company explained.

According to Microsoft, the fix is currently available for Windows 11 21H2 (KB5020387), Windows 10 (KB5020435), Windows 8.1, Windows 7, and Windows Server. However, Microsoft is still working to address the network connectivity issues on Windows 11 22H2.

Windows updates for SSL/TLS connection issues are available via the Microsoft Update Catalog

Microsoft notes that IT admins won’t be able to deploy the updates via Windows Updates, Windows Update for Business, or Windows Server Update Services (WSUS). The optional updates are only available to download in the Microsoft Update Catalog and must be installed manually.

Earlier this month, Microsoft confirmed that it’s investigating an issue that causes slower SMB read performance for large files in Windows 11 version 22H2 and slower speeds for local copies. As a workaround, the company suggests that users copying files from a remote PC via SMB can use the robocopy or xcopy commands with the /J (unbuffered IO) parameter.

Microsoft also acknowledged a compatibility issue with some printer drivers and Windows 11 version 22H2. Microsoft placed an upgrade block on all affected devices until the compatibility issue gets resolved.