Use DescribeAvailablePatches with a CLI

To get available patches

The following describe-available-patches example retrieves details about all available patches for Windows Server 2019 that have a MSRC severity of Critical.

aws ssm describe-available-patches \
    --filters "Key=PRODUCT,Values=WindowsServer2019" "Key=MSRC_SEVERITY,Values=Critical"

Output:

{
    "Patches": [
        {
            "Id": "fe6bd8c2-3752-4c8b-ab3e-1a7ed08767ba",
            "ReleaseDate": 1544047205.0,
            "Title": "2018-11 Update for Windows Server 2019 for x64-based Systems (KB4470788)",
            "Description": "Install this update to resolve issues in Windows. For a complete listing of the issues that are included in this update, see the associated Microsoft Knowledge Base article for more information. After you install this item, you may have to restart your computer.",
            "ContentUrl": "https://support.microsoft.com/en-us/kb/4470788",
            "Vendor": "Microsoft",
            "ProductFamily": "Windows",
            "Product": "WindowsServer2019",
            "Classification": "SecurityUpdates",
            "MsrcSeverity": "Critical",
            "KbNumber": "KB4470788",
            "MsrcNumber": "",
            "Language": "All"
        },
        {
            "Id": "c96115e1-5587-4115-b851-22baa46a3f11",
            "ReleaseDate": 1549994410.0,
            "Title": "2019-02 Security Update for Adobe Flash Player for Windows Server 2019 for x64-based Systems (KB4487038)",
            "Description": "A security issue has been identified in a Microsoft software product that could affect your system. You can help protect your system by installing this update from Microsoft. For a complete listing of the issues that are included in this update, see the associated Microsoft Knowledge Base article. After you install this update, you may have to restart your system.",
            "ContentUrl": "https://support.microsoft.com/en-us/kb/4487038",
            "Vendor": "Microsoft",
            "ProductFamily": "Windows",
            "Product": "WindowsServer2019",
            "Classification": "SecurityUpdates",
            "MsrcSeverity": "Critical",
            "KbNumber": "KB4487038",
            "MsrcNumber": "",
            "Language": "All"
        },
        ...
    ]
}

To get details of a specific patch

The following describe-available-patches example retrieves details about the specified patch.

aws ssm describe-available-patches \
    --filters "Key=PATCH_ID,Values=KB4480979"

Output:

{
    "Patches": [
        {
            "Id": "680861e3-fb75-432e-818e-d72e5f2be719",
            "ReleaseDate": 1546970408.0,
            "Title": "2019-01 Security Update for Adobe Flash Player for Windows Server 2016 for x64-based Systems (KB4480979)",
            "Description": "A security issue has been identified in a Microsoft software product that could affect your system. You can help protect your system by installing this update from Microsoft. For a complete listing of the issues that are included in this update, see the associated Microsoft Knowledge Base article. After you install this update, you may have to restart your system.",
            "ContentUrl": "https://support.microsoft.com/en-us/kb/4480979",
            "Vendor": "Microsoft",
            "ProductFamily": "Windows",
            "Product": "WindowsServer2016",
            "Classification": "SecurityUpdates",
            "MsrcSeverity": "Critical",
            "KbNumber": "KB4480979",
            "MsrcNumber": "",
            "Language": "All"
        }
    ]
}

For more information, see How Patch Manager Operations Work in the AWS Systems Manager User Guide.

Example 1: This example gets all available patches for Windows Server 2012 that have a MSRC severity of Critical. The syntax used by this example requires PowerShell version 3 or later.

$filter1 = @{Key="PRODUCT";Values=@("WindowsServer2012")}
$filter2 = @{Key="MSRC_SEVERITY";Values=@("Critical")}

Get-SSMAvailablePatch -Filter $filter1,$filter2

Output:

Classification : SecurityUpdates
ContentUrl     : https://support.microsoft.com/en-us/kb/2727528
Description    : A security issue has been identified that could allow an unauthenticated remote attacker to compromise your system and gain control
                 over it. You can help protect your system by installing this update from Microsoft. After you install this update, you may have to
                 restart your system.
Id             : 1eb507be-2040-4eeb-803d-abc55700b715
KbNumber       : KB2727528
Language       : All
MsrcNumber     : MS12-072
MsrcSeverity   : Critical
Product        : WindowsServer2012
ProductFamily  : Windows
ReleaseDate    : 11/13/2012 6:00:00 PM
Title          : Security Update for Windows Server 2012 (KB2727528)
Vendor         : Microsoft
...

Example 2: With PowerShell version 2, you must use New-Object to create each filter.

$filter1 = New-Object Amazon.SimpleSystemsManagement.Model.PatchOrchestratorFilter
$filter1.Key = "PRODUCT"
$filter1.Values = "WindowsServer2012"
$filter2 = New-Object Amazon.SimpleSystemsManagement.Model.PatchOrchestratorFilter
$filter2.Key = "MSRC_SEVERITY"
$filter2.Values = "Critical"

Get-SSMAvailablePatch -Filter $filter1,$filter2

Example 3: This example fetches all the updates which are released in last 20 days and applicable to products matching WindowsServer2019

Get-SSMAvailablePatch | Where-Object ReleaseDate -ge (Get-Date).AddDays(-20) | Where-Object Product -eq "WindowsServer2019" | Select-Object ReleaseDate, Product, Title

Output:

ReleaseDate         Product           Title
-----------         -------           -----
4/9/2019 5:00:12 PM WindowsServer2019 2019-04 Security Update for Adobe Flash Player for Windows Server 2019 for x64-based Systems (KB4493478)
4/9/2019 5:00:06 PM WindowsServer2019 2019-04 Cumulative Update for Windows Server 2019 for x64-based Systems (KB4493509)
4/2/2019 5:00:06 PM WindowsServer2019 2019-03 Servicing Stack Update for Windows Server 2019 for x64-based Systems (KB4493510)