diff --git a/.azure-pipelines/ci-build.yml b/.azure-pipelines/ci-build.yml
index 835d60c9fd7..a3077918519 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 801e7ebd72b..68b47ade3de 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 0b64943de14..d26de8160cc 100644
--- a/.azure-pipelines/common-templates/install-tools.yml
+++ b/.azure-pipelines/common-templates/install-tools.yml
@@ -61,6 +61,21 @@ 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
+      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).
+        . "$(Build.SourcesDirectory)/tools/Get-CfsFeedCredential.ps1"
+        Register-CfsFeed
+        Get-PSRepository -Name PowerShell_V2_Build | Format-List Name, SourceLocation, InstallationPolicy, Trusted
+    env:
+      SYSTEM_ACCESSTOKEN: $(System.AccessToken)
+
   - task: Npm@1
     displayName: Install AutoRest
     inputs:
diff --git a/.azure-pipelines/weekly-generation.yml b/.azure-pipelines/weekly-generation.yml
index 6be0893c0c6..5cf86adc267 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: $(System.AccessToken)
 trigger: none
 pr: none
 schedules:
diff --git a/tools/BuildModule.ps1 b/tools/BuildModule.ps1
index e6485f5dfd4..3ba051e5e82 100644
--- a/tools/BuildModule.ps1
+++ b/tools/BuildModule.ps1
@@ -66,7 +66,11 @@ if ($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
+# 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'] = $__cfsCred }
+$ExistingModule = Find-Module $ModuleFullName -Repository (Get-CfsFeedName) -ErrorAction SilentlyContinue
 $ModuleGuid = ($null -eq $ExistingModule) ? (New-Guid).Guid : $ExistingModule.AdditionalMetadata.GUID
 
 [HashTable]$ModuleManifestSettings = @{
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..9356ff906ed
--- /dev/null
+++ b/tools/Get-CfsFeedCredential.ps1
@@ -0,0 +1,41 @@
+# 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
+    if (-not (Get-PSRepository -Name $script:CfsFeedName -ErrorAction SilentlyContinue)) {
+        Register-PSRepository -Name $script:CfsFeedName -SourceLocation $script:CfsFeedUrl -InstallationPolicy Trusted -Credential $cred
+    }
+}
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