diff --git a/.azure-pipelines/ci-build.yml b/.azure-pipelines/ci-build.yml
index 95d09b92252..41d2d07e867 100644
--- a/.azure-pipelines/ci-build.yml
+++ b/.azure-pipelines/ci-build.yml
@@ -31,6 +31,9 @@ variables:
   REGISTRY: 'msgraphprodregistry.azurecr.io'
   REGISTRY_NAME: 'msgraphprodregistry'
   IMAGE_NAME: 'public/microsoftgraph/powershell'
+  # Expose the build identity's token as a process-wide env var so generation scripts (including
+  # ForEach-Object -Parallel runspaces) can authenticate to the private CFS module feed. (CFSClean)
+  SYSTEM_ACCESSTOKEN: $(System.AccessToken)
 
 trigger:
   branches:
diff --git a/.azure-pipelines/command-metadata-refresh.yml b/.azure-pipelines/command-metadata-refresh.yml
index cfa6f32361c..2312fb284e8 100644
--- a/.azure-pipelines/command-metadata-refresh.yml
+++ b/.azure-pipelines/command-metadata-refresh.yml
@@ -31,6 +31,9 @@ variables:
   BuildAgent: ${{ parameters.BuildAgent }}
   Branch: "ModuleCommandMetadataRefresh"
   BaseBranch: ${{ parameters.BaseBranch }}
+  # Expose the build identity's token as a process-wide env var so generation scripts (including
+  # ForEach-Object -Parallel runspaces) can authenticate to the private CFS module feed. (CFSClean)
+  SYSTEM_ACCESSTOKEN: $(System.AccessToken)
 
 trigger:
   branches:
diff --git a/.azure-pipelines/common-templates/install-tools.yml b/.azure-pipelines/common-templates/install-tools.yml
index c1f65040840..e8c44f83890 100644
--- a/.azure-pipelines/common-templates/install-tools.yml
+++ b/.azure-pipelines/common-templates/install-tools.yml
@@ -64,6 +64,48 @@ steps:
         Copy-Item -Path $src -Destination $dst -Force
         Write-Host "Copied npm config to $dst"
 
+  - task: PowerShell@2
+    displayName: Register private module feed (CFSClean)
+    inputs:
+      targetType: inline
+      pwsh: true
+      errorActionPreference: continue
+      script: |
+        # Register the private Azure Artifacts feed (PowerShell Gallery upstream) as a Trusted
+        # PSRepository so generation-time Install-Module/Find-Module resolve through it instead of
+        # the public PowerShell Gallery. Persisted for the job (visible to later steps + runspaces).
+        # errorActionPreference is 'continue' because PackageManagement emits benign non-terminating
+        # errors (e.g. source-already-registered) that would otherwise fail the task; Register-CfsFeed
+        # throws on genuine failure, which still fails the step.
+        . "$(Build.SourcesDirectory)/tools/Get-CfsFeedCredential.ps1"
+        Unregister-PublicPSGallery
+        Register-CfsFeed
+        Get-PSRepository | Format-List Name, SourceLocation, InstallationPolicy, Trusted
+        # PowerShellGet bootstraps the NuGet provider via a native tool during registration, which can
+        # leave a stray non-zero $LASTEXITCODE that fails the task even though registration succeeded.
+        # Register-CfsFeed throws on genuine failure (halting before this line), so reset it here.
+        $global:LASTEXITCODE = 0
+    env:
+      SYSTEM_ACCESSTOKEN: $(System.AccessToken)
+
+  - task: PowerShell@2
+    displayName: Pre-install generation tooling modules (CFSClean)
+    inputs:
+      targetType: inline
+      pwsh: true
+      errorActionPreference: continue
+      script: |
+        # Install PlatyPS / Pester / powershell-yaml / PowerHTML from the private feed up-front, in this
+        # controlled credential context, so the lazy Install-Module calls during generation are skipped
+        # by their Get-Module -ListAvailable guards (authenticated private-feed installs are fragile in
+        # the parallel generation runspaces).
+        . "$(Build.SourcesDirectory)/tools/Get-CfsFeedCredential.ps1"
+        Install-CfsToolingModules
+        Get-Module -ListAvailable -Name PlatyPS, Pester, powershell-yaml, PowerHTML | Format-Table Name, Version, Path -AutoSize
+        $global:LASTEXITCODE = 0
+    env:
+      SYSTEM_ACCESSTOKEN: $(System.AccessToken)
+
   - task: Npm@1
     displayName: Install AutoRest
     retryCountOnTaskFailure: 2
diff --git a/.azure-pipelines/generation-templates/authentication-module.yml b/.azure-pipelines/generation-templates/authentication-module.yml
index 4dc2d7148d1..df35650f367 100644
--- a/.azure-pipelines/generation-templates/authentication-module.yml
+++ b/.azure-pipelines/generation-templates/authentication-module.yml
@@ -20,6 +20,8 @@ steps:
       pwsh: true
       script: |
         . $(System.DefaultWorkingDirectory)/tools/GenerateAuthenticationModule.ps1 -EnableSigning:$${{ parameters.Sign }} -Build
+    env:
+      SYSTEM_ACCESSTOKEN: $(System.AccessToken)
 
   - ${{ if eq(parameters.Test, true) }}:
       - task: PowerShell@2
diff --git a/.azure-pipelines/generation-templates/meta-module.yml b/.azure-pipelines/generation-templates/meta-module.yml
index f4310d987d2..fcf9a876652 100644
--- a/.azure-pipelines/generation-templates/meta-module.yml
+++ b/.azure-pipelines/generation-templates/meta-module.yml
@@ -1,4 +1,4 @@
-# Copyright (c) Microsoft Corporation. All rights reserved.
+# Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
 
 parameters:
@@ -50,3 +50,5 @@ steps:
           pwsh: true
           script: |
             . $(System.DefaultWorkingDirectory)/tools/GenerateMetaModule.ps1 -Pack -ArtifactsLocation $(Build.ArtifactStagingDirectory)
+        env:
+          SYSTEM_ACCESSTOKEN: $(System.AccessToken)
diff --git a/.azure-pipelines/generation-templates/workload-modules.yml b/.azure-pipelines/generation-templates/workload-modules.yml
index 47cbc030be1..4a5f5443764 100644
--- a/.azure-pipelines/generation-templates/workload-modules.yml
+++ b/.azure-pipelines/generation-templates/workload-modules.yml
@@ -1,4 +1,4 @@
-# Copyright (c) Microsoft Corporation. All rights reserved.
+# Copyright (c) Microsoft Corporation. All rights reserved.
 # Licensed under the MIT License.
 
 parameters:
@@ -20,6 +20,8 @@ steps:
       pwsh: true
       script: |
         . $(System.DefaultWorkingDirectory)/tools/GenerateModules.ps1 -EnableSigning:$${{ parameters.Sign }} -Build -ExcludeExampleTemplates -ExcludeNotesSection
+    env:
+      SYSTEM_ACCESSTOKEN: $(System.AccessToken)
 
   - template: ../common-templates/guardian-analyzer.yml
 
@@ -94,3 +96,5 @@ steps:
           pwsh: true
           script: |
             . $(System.DefaultWorkingDirectory)/tools/GenerateModules.ps1 -SkipGeneration -Pack -ArtifactsLocation $(Build.ArtifactStagingDirectory)
+        env:
+          SYSTEM_ACCESSTOKEN: $(System.AccessToken)
diff --git a/.azure-pipelines/weekly-generation.yml b/.azure-pipelines/weekly-generation.yml
index e859bc415c8..3583c5e6db0 100644
--- a/.azure-pipelines/weekly-generation.yml
+++ b/.azure-pipelines/weekly-generation.yml
@@ -42,6 +42,9 @@ parameters:
 variables:
   BaseBranch: ${{ parameters.BaseBranch }}
   BuildAgent: ${{ parameters.BuildAgent }}
+  # Expose the build identity's token as a process-wide env var so generation scripts (including
+  # ForEach-Object -Parallel runspaces) can authenticate to the private CFS module feed. (CFSClean)
+  SYSTEM_ACCESSTOKEN: $(System.AccessToken)
 trigger: none
 pr: none
 schedules:
diff --git a/src/Authentication/Authentication/test/Connect-MgGraph.Tests.ps1 b/src/Authentication/Authentication/test/Connect-MgGraph.Tests.ps1
index de52fcaef5a..1e257e1d5b8 100644
--- a/src/Authentication/Authentication/test/Connect-MgGraph.Tests.ps1
+++ b/src/Authentication/Authentication/test/Connect-MgGraph.Tests.ps1
@@ -7,7 +7,11 @@ BeforeAll {
     $ModulePath = Join-Path $PSScriptRoot "..\artifacts\$ModuleName.psd1"
     Import-Module $ModulePath -Force
     $RandomClientId = (New-Guid).Guid
-    Install-Module Az.Accounts -Repository PSGallery -Scope CurrentUser -Force -AllowClobber
+    # CFSClean: Az.Accounts is pre-installed from the private feed in install-tools (public PSGallery is
+    # unregistered under network isolation), so only install here if it is somehow not already present.
+    if (-not (Get-Module -Name Az.Accounts -ListAvailable)) {
+        Install-Module Az.Accounts -Scope CurrentUser -Force -AllowClobber
+    }
 }
 Describe 'Connect-MgGraph ParameterSets' {
     BeforeAll {
diff --git a/tools/BuildModule.ps1 b/tools/BuildModule.ps1
index e6485f5dfd4..7aa82f20b81 100644
--- a/tools/BuildModule.ps1
+++ b/tools/BuildModule.ps1
@@ -66,8 +66,12 @@ if ($ModuleFullName -ne "Microsoft.Graph.Authentication") {
 }
 
 # Lock module GUID. See https://github.com/Azure/autorest.powershell/issues/981.
-$ExistingModule = Find-Module $ModuleFullName -Repository PSGallery -ErrorAction SilentlyContinue
-$ModuleGuid = ($null -eq $ExistingModule) ? (New-Guid).Guid : $ExistingModule.AdditionalMetadata.GUID
+# CFSClean: the private feed does not surface the module GUID via Find-Module's AdditionalMetadata,
+# so read it from the package published on the feed. Mint a new GUID only when unpublished (matches
+# the original "first publish" behaviour) without ever querying the public PowerShell Gallery.
+. (Join-Path $PSScriptRoot 'Get-CfsFeedCredential.ps1')
+$ModuleGuid = Get-CfsModuleGuid -Name $ModuleFullName
+if ([string]::IsNullOrWhiteSpace($ModuleGuid)) { $ModuleGuid = (New-Guid).Guid }
 
 [HashTable]$ModuleManifestSettings = @{
     Guid          = $ModuleGuid
diff --git a/tools/GenerateAuthenticationModule.ps1 b/tools/GenerateAuthenticationModule.ps1
index 6d71c22f35d..18939a6ff0c 100644
--- a/tools/GenerateAuthenticationModule.ps1
+++ b/tools/GenerateAuthenticationModule.ps1
@@ -2,7 +2,7 @@
 # Licensed under the MIT License.
 [CmdletBinding()]
 Param(
-  [string] $RepositoryName = "PSGallery",
+  [string] $RepositoryName = "PowerShell_V2_Build",
   [string] $RepositoryApiKey,
   [string] $ArtifactsLocation = (Join-Path $PSScriptRoot "..\artifacts\"),
   [switch] $Build,
diff --git a/tools/GenerateHelp.ps1 b/tools/GenerateHelp.ps1
index 24750d984f1..1138a96912d 100644
--- a/tools/GenerateHelp.ps1
+++ b/tools/GenerateHelp.ps1
@@ -7,8 +7,12 @@ Param(
     [string] $ModuleMappingConfigPath = (Join-Path $PSScriptRoot "..\config\ModulesMapping.jsonc")
 )
 # Install PlatyPS
+# CFSClean: install tooling modules from the private feed (PowerShell Gallery upstream).
+. (Join-Path $PSScriptRoot 'Get-CfsFeedCredential.ps1')
+$__cfsCred = Get-CfsFeedCredential
+if ($null -ne $__cfsCred) { $PSDefaultParameterValues['Install-Module:Credential'] = $__cfsCred }
 if (!(Get-Module -Name PlatyPS -ListAvailable)) {
-    Install-Module PlatyPS -Force
+    Install-Module PlatyPS -Repository (Get-CfsFeedName) -Force
 }
 Import-Module PlatyPS -Force -Scope Global
 
diff --git a/tools/GenerateMetaModule.ps1 b/tools/GenerateMetaModule.ps1
index a921fb8cb25..1419db24f47 100644
--- a/tools/GenerateMetaModule.ps1
+++ b/tools/GenerateMetaModule.ps1
@@ -6,7 +6,7 @@ Param(
     [ValidateSet("v1.0", "beta")]
     $ApiVersion = @("v1.0", "beta"),
     [string] $RepositoryApiKey,
-    [string] $RepositoryName = "PSGallery",
+    [string] $RepositoryName = "PowerShell_V2_Build",
     [string] $ArtifactsLocation = (Join-Path $PSScriptRoot "..\artifacts\"),
     [switch] $Pack,
     [switch] $Publish,
diff --git a/tools/GenerateRollUpModule.ps1 b/tools/GenerateRollUpModule.ps1
index 25e779bdf6b..7a76433b230 100644
--- a/tools/GenerateRollUpModule.ps1
+++ b/tools/GenerateRollUpModule.ps1
@@ -4,7 +4,7 @@
 [CmdletBinding()]
 Param(
     [string] $RepositoryApiKey,
-    [string] $RepositoryName = "PSGallery",
+    [string] $RepositoryName = "PowerShell_V2_Build",
     [string] $ArtifactsLocation = (Join-Path $PSScriptRoot "..\artifacts\"),
     [string] $ModuleMappingConfigPath = (Join-Path $PSScriptRoot "..\config\ModulesMapping.jsonc"),
     [int] $ModulePreviewNumber = -1,
@@ -19,6 +19,14 @@ enum VersionState {
 }
 $ErrorActionPreference = 'Stop'
 $LASTEXITCODE = $null
+# CFSClean: authenticate module installs/queries to the private feed (credential from the build token).
+. (Join-Path $PSScriptRoot 'Get-CfsFeedCredential.ps1')
+$__cfsCred = Get-CfsFeedCredential
+if ($null -ne $__cfsCred) {
+    $PSDefaultParameterValues['Find-Module:Credential']    = $__cfsCred
+    $PSDefaultParameterValues['Install-Module:Credential'] = $__cfsCred
+    $PSDefaultParameterValues['Save-Module:Credential']    = $__cfsCred
+}
 if ($PSEdition -ne 'Core') {
     Write-Error 'This script requires PowerShell Core to execute. [Note] Generated cmdlets will work in both PowerShell Core or Windows PowerShell.'
 }
diff --git a/tools/Get-CfsFeedCredential.ps1 b/tools/Get-CfsFeedCredential.ps1
new file mode 100644
index 00000000000..b6f62ae54ae
--- /dev/null
+++ b/tools/Get-CfsFeedCredential.ps1
@@ -0,0 +1,138 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+<#
+.SYNOPSIS
+    Shared helpers to route PowerShell module installs/queries through the private Azure Artifacts
+    feed (CFSClean network isolation) instead of the public PowerShell Gallery.
+
+.DESCRIPTION
+    The private feed `PowerShell_V2_Build` has a PowerShell Gallery upstream, so it can serve both
+    the internally published Graph modules and public tooling modules (Pester, PlatyPS,
+    powershell-yaml, PowerHTML). Reads the credential from the process-wide $env:SYSTEM_ACCESSTOKEN
+    (mapped from $(System.AccessToken) at the pipeline `variables:` level), so it works inside
+    ForEach-Object -Parallel runspaces where session state is not inherited.
+#>
+
+$script:CfsFeedName = 'PowerShell_V2_Build'
+$script:CfsFeedUrl  = 'https://microsoftgraph.pkgs.visualstudio.com/0985d294-5762-4bc2-a565-161ef349ca3e/_packaging/PowerShell_V2_Build/nuget/v2'
+
+function Get-CfsFeedName {
+    return $script:CfsFeedName
+}
+
+function Get-CfsFeedCredential {
+    # Returns a PSCredential built from the build identity's access token, or $null when the token is
+    # unavailable (e.g. local dev), in which case callers fall back to their default behaviour.
+    if ([string]::IsNullOrWhiteSpace($env:SYSTEM_ACCESSTOKEN)) {
+        return $null
+    }
+    $token = ConvertTo-SecureString $env:SYSTEM_ACCESSTOKEN -AsPlainText -Force
+    return [System.Management.Automation.PSCredential]::new('azure', $token)
+}
+
+function Register-CfsFeed {
+    # Registers the private feed as a Trusted PSRepository (idempotent). Persisted under the user's
+    # PowerShellGet config, so a single registration per job is visible to later steps and runspaces.
+    $cred = Get-CfsFeedCredential
+    # Get-PSRepository can lazily return nothing in a fresh session even when the source is already
+    # persisted (registered by an earlier step/runspace). Get-PackageSource surfaces that collision,
+    # so check both before attempting to register.
+    if ((Get-PSRepository -Name $script:CfsFeedName -ErrorAction SilentlyContinue) -or
+        (Get-PackageSource -Name $script:CfsFeedName -ErrorAction SilentlyContinue)) {
+        Write-Host "Package source '$($script:CfsFeedName)' is already registered; skipping."
+        return
+    }
+    # The "already added" collision is a non-terminating error emitted by an internal PackageManagement
+    # cmdlet that bypasses -ErrorAction Stop (and would otherwise fail the task under its default Stop
+    # preference), so redirect every stream to null and verify the outcome instead of trusting the call.
+    Register-PSRepository -Name $script:CfsFeedName -SourceLocation $script:CfsFeedUrl -InstallationPolicy Trusted -Credential $cred -ErrorAction SilentlyContinue *> $null
+    if (-not (Get-PSRepository -Name $script:CfsFeedName -ErrorAction SilentlyContinue)) {
+        throw "Failed to register PSRepository '$($script:CfsFeedName)'."
+    }
+    Write-Host "Registered PSRepository '$($script:CfsFeedName)'."
+}
+
+function Unregister-PublicPSGallery {
+    # Remove the public PowerShell Gallery. Call this FIRST, before any other PowerShellGet operation,
+    # so PSGallery is gone before an enumeration resolves its source location (which egresses to
+    # www.powershellgallery.com - a CFSClean2 violation). Unregister-PackageSource removes the source
+    # entry without resolving its location; the PSRepository fallback covers the PowerShellGet view.
+    Unregister-PackageSource -Name 'PSGallery' -Force -ErrorAction SilentlyContinue *> $null
+    if (Get-PSRepository -Name 'PSGallery' -ErrorAction SilentlyContinue) {
+        Unregister-PSRepository -Name 'PSGallery' -ErrorAction SilentlyContinue *> $null
+    }
+    Write-Host "Removed public 'PSGallery'; module installs now resolve only through '$($script:CfsFeedName)'."
+    $global:LASTEXITCODE = 0
+}
+
+function Install-CfsToolingModules {
+    # Pre-installs the generation-time tooling modules from the private feed once, in this controlled
+    # credential context, so the lazy Install-Module calls during generation are skipped by their
+    # Get-Module -ListAvailable guards. This avoids repeating authenticated private-feed installs across
+    # many generation steps and parallel runspaces (where credential/source resolution is fragile).
+    $cred = Get-CfsFeedCredential
+    $tooling = @(
+        @{ Name = 'PlatyPS' },
+        @{ Name = 'Pester'; SkipPublisherCheck = $true },
+        @{ Name = 'powershell-yaml'; AcceptLicense = $true },
+        @{ Name = 'PowerHTML' },
+        @{ Name = 'Az.Accounts' }
+    )
+    foreach ($t in $tooling) {
+        if (Get-Module -Name $t.Name -ListAvailable) {
+            Write-Host "Tooling module '$($t.Name)' already available; skipping."
+            continue
+        }
+        $params = @{ Name = $t.Name; Repository = $script:CfsFeedName; Scope = 'AllUsers'; Force = $true; AllowClobber = $true }
+        if ($null -ne $cred) { $params.Credential = $cred }
+        if ($t.SkipPublisherCheck) { $params.SkipPublisherCheck = $true }
+        if ($t.AcceptLicense) { $params.AcceptLicense = $true }
+        Install-Module @params
+        Write-Host "Installed tooling module '$($t.Name)' from '$($script:CfsFeedName)'."
+    }
+    $global:LASTEXITCODE = 0
+}
+
+function Get-CfsModuleGuid {
+    # Returns the GUID of the module already published to the private feed, or $null when it is not
+    # published there or the GUID cannot be determined (callers then mint a fresh GUID, preserving the
+    # original "first publish" behaviour). The Azure Artifacts feed does not surface the GUID via
+    # Find-Module's AdditionalMetadata (public PS Gallery does), so this downloads the published package
+    # directly over HTTP from the feed's NuGet v2 OData endpoint and reads the GUID from its manifest.
+    # Using raw HTTP (not Find-Module/Save-Package) avoids PowerShellGet/PackageManagement source
+    # resolution, which is unreliable in the generation runspaces, and never touches public PS Gallery.
+    # The module GUID is version-independent (locked), so any published version's manifest is fine.
+    param(
+        [Parameter(Mandatory)][string] $Name
+    )
+    if ([string]::IsNullOrWhiteSpace($env:SYSTEM_ACCESSTOKEN)) { return $null }
+    $headers = @{ Authorization = 'Basic ' + [Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes("azure:$($env:SYSTEM_ACCESSTOKEN)")) }
+    $tmp = Join-Path ([System.IO.Path]::GetTempPath()) ("cfsguid_" + [System.Guid]::NewGuid().ToString('N'))
+    try {
+        New-Item -ItemType Directory -Path $tmp -Force | Out-Null
+        $findUri = "$($script:CfsFeedUrl)/FindPackagesById()?id='$Name'"
+        $resp = Invoke-WebRequest -Uri $findUri -Headers $headers -UseBasicParsing -ErrorAction Stop
+        [xml]$xml = $resp.Content
+        $entry = @($xml.feed.entry) | Where-Object { $_.content.src } | Select-Object -Last 1
+        if ($null -eq $entry) { return $null }
+        $nupkgPath = Join-Path $tmp "$Name.nupkg"
+        Invoke-WebRequest -Uri $entry.content.src -Headers $headers -OutFile $nupkgPath -UseBasicParsing -ErrorAction Stop
+        Add-Type -AssemblyName System.IO.Compression.FileSystem
+        $zip = [System.IO.Compression.ZipFile]::OpenRead($nupkgPath)
+        try {
+            $psd1 = $zip.Entries | Where-Object { $_.Name -eq "$Name.psd1" } | Select-Object -First 1
+            if ($null -eq $psd1) { return $null }
+            $reader = [System.IO.StreamReader]::new($psd1.Open())
+            try { $content = $reader.ReadToEnd() } finally { $reader.Dispose() }
+        }
+        finally { $zip.Dispose() }
+        $match = [regex]::Match($content, "(?im)^\s*GUID\s*=\s*['`"]([0-9a-fA-F-]{36})['`"]")
+        if ($match.Success) { return $match.Groups[1].Value }
+        return $null
+    }
+    catch { return $null }
+    finally {
+        Remove-Item -Path $tmp -Recurse -Force -ErrorAction SilentlyContinue
+    }
+}
diff --git a/tools/ImportExamples.ps1 b/tools/ImportExamples.ps1
index 030b224e757..3212d68e1f8 100644
--- a/tools/ImportExamples.ps1
+++ b/tools/ImportExamples.ps1
@@ -575,13 +575,17 @@ function Get-ExistingCorrectExamples {
 }
 $RetainedExamples = New-Object Collections.Generic.List[string]
 
+# CFSClean: install tooling modules from the private feed (PowerShell Gallery upstream).
+. (Join-Path $PSScriptRoot 'Get-CfsFeedCredential.ps1')
+$__cfsCred = Get-CfsFeedCredential
+if ($null -ne $__cfsCred) { $PSDefaultParameterValues['Install-Module:Credential'] = $__cfsCred }
 if (!(Get-Module "powershell-yaml" -ListAvailable -ErrorAction SilentlyContinue)) {
-    Install-Module "powershell-yaml" -AcceptLicense -Scope CurrentUser -Force
+    Install-Module "powershell-yaml" -Repository (Get-CfsFeedName) -AcceptLicense -Scope CurrentUser -Force
 }
 
 If (-not (Get-Module -ErrorAction Ignore -ListAvailable PowerHTML)) {
     Write-Verbose "Installing PowerHTML module for the current user..."
-    Install-Module PowerHTML -ErrorAction Stop -Scope CurrentUser -Force
+    Install-Module PowerHTML -Repository (Get-CfsFeedName) -ErrorAction Stop -Scope CurrentUser -Force
 }
 Import-Module -ErrorAction Stop PowerHTML
 
diff --git a/tools/TestModule.ps1 b/tools/TestModule.ps1
index adfb15d7576..081f9ca81d8 100644
--- a/tools/TestModule.ps1
+++ b/tools/TestModule.ps1
@@ -5,8 +5,12 @@ param([string] $ModulePath, [string] $ModuleName, [string] $ModuleTestsPath, [sw
 $ErrorActionPreference = 'Stop'
 
 # Install Pester
+# CFSClean: install tooling modules from the private feed (PowerShell Gallery upstream).
+. (Join-Path $PSScriptRoot 'Get-CfsFeedCredential.ps1')
+$__cfsCred = Get-CfsFeedCredential
+if ($null -ne $__cfsCred) { $PSDefaultParameterValues['Install-Module:Credential'] = $__cfsCred }
 if (!(Get-Module -Name Pester -ListAvailable)) {
-    Install-Module -Name Pester -Force -SkipPublisherCheck
+    Install-Module -Name Pester -Repository (Get-CfsFeedName) -Force -SkipPublisherCheck
 }
 
 if(-not $Isolated) {
diff --git a/tools/UpdateOpenApi.ps1 b/tools/UpdateOpenApi.ps1
index 64d4e4f154c..1b98f04ca41 100644
--- a/tools/UpdateOpenApi.ps1
+++ b/tools/UpdateOpenApi.ps1
@@ -15,8 +15,11 @@ if ($PSEdition -ne 'Core') {
 }
 
 if (!(Get-Module powershell-yaml -ListAvailable)) {
-    # Install Powershell-yaml
-    Install-Module powershell-yaml -Force
+    # Install Powershell-yaml from the private feed (PowerShell Gallery upstream). (CFSClean)
+    . (Join-Path $PSScriptRoot 'Get-CfsFeedCredential.ps1')
+    $__cfsCred = Get-CfsFeedCredential
+    if ($null -ne $__cfsCred) { $PSDefaultParameterValues['Install-Module:Credential'] = $__cfsCred }
+    Install-Module powershell-yaml -Repository (Get-CfsFeedName) -Force
 }
 
 $GraphVersion = "v1.0"
diff --git a/tools/ValidateUpdatedModuleVersion.ps1 b/tools/ValidateUpdatedModuleVersion.ps1
index b916f78f5b6..69d925b1725 100644
--- a/tools/ValidateUpdatedModuleVersion.ps1
+++ b/tools/ValidateUpdatedModuleVersion.ps1
@@ -4,7 +4,7 @@
 param(
     [Parameter()][ValidateNotNullOrEmpty()][string] $ModuleName,
     [Parameter()][ValidateNotNullOrEmpty()][string] $NextVersion,
-    [Parameter()][string] $PSRepository = "PSGallery",
+    [Parameter()][string] $PSRepository = "PowerShell_V2_Build",
     [int] $ModulePreviewNumber = -1
 )
 enum VersionState {
@@ -18,6 +18,15 @@ enum VersionState {
 Import-Module PackageManagement
 Import-Module PowerShellGet
 
+# CFSClean: authenticate module queries to the private feed (credential from the build token).
+. (Join-Path $PSScriptRoot 'Get-CfsFeedCredential.ps1')
+$__cfsCred = Get-CfsFeedCredential
+if ($null -ne $__cfsCred) {
+    $PSDefaultParameterValues['Find-Module:Credential']    = $__cfsCred
+    $PSDefaultParameterValues['Install-Module:Credential'] = $__cfsCred
+    $PSDefaultParameterValues['Save-Module:Credential']    = $__cfsCred
+}
+
 $AllowPreRelease = $true
 if($ModulePreviewNumber -eq -1) {
     $AllowPreRelease = $false
diff --git a/tools/Versions/BumpModuleVersion.ps1 b/tools/Versions/BumpModuleVersion.ps1
index 6325b5ddc0b..411fe80b426 100644
--- a/tools/Versions/BumpModuleVersion.ps1
+++ b/tools/Versions/BumpModuleVersion.ps1
@@ -7,12 +7,17 @@ Param(
     [switch] $BumpBetaModule,
     [switch] $BumpAuthModule,
     [string] $PreReleaseTag,
-    [string] $Repository = "PSGallery"
+    [string] $Repository = "PowerShell_V2_Build"
 )
 $ErrorActionPreference = "Stop"
 
 . $PSScriptRoot\SetModuleVersion.ps1
 
+# CFSClean: authenticate module queries to the private feed (credential from the build token).
+. (Join-Path $PSScriptRoot '..\Get-CfsFeedCredential.ps1')
+$__cfsCred = Get-CfsFeedCredential
+if ($null -ne $__cfsCred) { $PSDefaultParameterValues['Find-Module:Credential'] = $__cfsCred }
+
 # Calculate and bump v1.0 module version
 if ($BumpV1Module.IsPresent) {
     $v1Module = Find-Module "Microsoft.Graph" -Repository $Repository -AllowPrerelease