script to get latest Cumulative update for various builds of Windows 10 and Windows Server 2016

Get-LatestUpdate.ps1

<#
.SYNOPSIS
Get the latest Cumulative update for Windows

.DESCRIPTION
This script will return the list of Cumulative updates for Windows 10 and Windows Server 2016 from the Microsoft Update Catalog.

.NOTES
Copyright Keith Garner (KeithGa@DeploymentLive.com), All rights reserved.

.LINK
https://support.microsoft.com/en-us/help/4000823

.EXAMPLE
Get the latest Cumulative Update for Windows 10 x64

.\Get-LatestUpdate.ps1 

.PARAMETER Build
Windows 10 Build Number used to filter avaible Downloads

    10240 - Windows 10 Version 1507 
    10586 - Windows 10 Version 1511 
    14393 - Windows 10 Version 1607 and Windows Server 2016
    15063 - Windows 10 Version 1703
    16299 - WIndows 10 Version 1709
    
.PARAMETER Filter
Specify a specific search filter to change the target update behaviour. The default will only Cumulative updates for x86 and x64.

If Mulitple Filters are specified, only string that match *ALL* filters will be selected.

    Cumulative - Download Cumulative updates.
    Delta - Download Delta updates.
    x86 - Download x86
    x64 - Download x64

.EXAMPLE
Get the latest Cumulative Update for Windows 10 x86

.\Get-LatestUpdate.ps1 -Filter 'Cumulative','x86'

.EXAMPLE

Get the latest Cumulative Update for Windows Server 2016

.\Get-LatestUpdate.ps1 -Filter 'Cumulative','x64' -Build 14393

.EXAMPLE

Get the latest Cumulative Updates for Windows 10 (both x86 and x64) and download to the %TEMP% directory.

.\Get-LatestUpdate.ps1 | Start-BitsTransfer -Destination $env:Temp

#>

[CmdletBinding()]
Param(
    [Parameter(Mandatory=$False, HelpMessage="JSON source for the update KB articles.")]
    [string] $StartKB = 'https://support.microsoft.com/app/content/api/content/asset/en-us/4000816',

    [Parameter(Mandatory=$False, HelpMessage="Windows build number.")]
    [ValidateSet('16299','15063','14393','10586','10240')]
    [string] $Build = '16299',

    [Parameter(Mandatory=$False, HelpMessage="Windows update Catalog Search Filter.")]
    [ValidateSet('x64','x86','Cumulative','Delta',$null)]
    [string[]] $Filter = @( "Cumulative" )

)

#region Support Routine

Function Select-LatestUpdate {

    [CmdletBinding( SupportsShouldProcess )]
    Param(
        [Parameter( Mandatory, ValueFromPipeline )]
        $Updates
    )
    
    
    BEGIN { 
        $MaxObject = $null
        $MaxValue = [version]::new("0.0")
    }
    PROCESS {
        ForEach ( $Update in $updates ) {
            Select-String -InputObject $Update -AllMatches -Pattern "(\d+\.)?(\d+\.)?(\d+\.)?(\*|\d+)" |
            ForEach-Object { $_.matches.value } |
            ForEach-Object { $_ -as [version] } |
            ForEach-Object { 
                if ( $_ -gt $MaxValue ) { 
                    $MaxObject = $Update
                    $MaxValue = $_ 
                }
            }
        }
    }
    END { 
        $MaxObject | Write-Output 
    }
}

#endregion

#region Find the KB Article Number

Write-Verbose "Downloading $StartKB to retrieve the list of updates."
$kbID = Invoke-WebRequest -Uri $StartKB |
    Select-Object -ExpandProperty Content |
    ConvertFrom-Json |
    Select-Object -ExpandProperty Links |
    Where-Object level -eq 2 |
    Where-Object text -match $BUild |
    Select-LatestUpdate |
    Select-Object -First 1

#endregion

#region get the download link from Windows Update

Write-Verbose "Found ID: KB$($kbID.articleID)"
$kbObj = Invoke-WebRequest -Uri "http://www.catalog.update.microsoft.com/Search.aspx?q=KB$($KBID.articleID)" 

$Available_KBIDs = $kbObj.InputFields | 
    Where-Object { $_.type -eq 'Button' -and $_.Value -eq 'Download' } | 
    Select-Object -ExpandProperty  ID

$Available_KBIDs | out-string | write-verbose

$kbGUIDs = $kbObj.Links | 
    Where-Object ID -match '_link' |
    Where-Object { $_.OuterHTML -match ( "(?=.*" + ( $Filter -join ")(?=.*" ) + ")" ) } |
    ForEach-Object { $_.id.replace('_link','') } |
    Where-Object { $_ -in $Available_KBIDs }

foreach ( $kbGUID in $kbGUIDs )
{
    Write-Verbose "`t`tDownload $kbGUID"
    $Post = @{ size = 0; updateID = $kbGUID; uidInfo = $kbGUID } | ConvertTo-Json -Compress
    $PostBody = @{ updateIDs = "[$Post]" } 
    Invoke-WebRequest -Uri 'http://www.catalog.update.microsoft.com/DownloadDialog.aspx' -Method Post -Body $postBody |
        Select-Object -ExpandProperty Content |
        Select-String -AllMatches -Pattern "(http[s]?\://download\.windowsupdate\.com\/[^\'\""]*)" | 
        Select-Object -Unique |
        ForEach-Object { [PSCustomObject] @{ Source = $_.matches.value } }  # Output for BITS
}

#endregion

transferred to https://github.com/turboBasic/Update-Windows repo