diff --git a/NuGet.config b/NuGet.config
index 8d2d351914d014..163d80df177f51 100644
--- a/NuGet.config
+++ b/NuGet.config
@@ -12,6 +12,16 @@
       one as a template. The following line is a marker to insert the test restore sources.
     -->
     <!-- TEST_RESTORE_SOURCES_INSERTION_LINE -->
+    <!-- Local nupkgs for validating dotnet/xharness PR #1597 (NativeAOT POC).
+         Absolute path because the workload-testing SDK generates restore projects
+         in deep nested directories, and NuGet re-resolves relative source paths
+         against the generated nuget.config's location, not against this one.
+         /__w/1/s/ is the dnceng-public AzDO Linux/macOS agent workspace.
+         D:\a\1\s is the Windows agent equivalent. Both entries are listed; only
+         the matching one will resolve, the other is silently ignored.
+         Remove these entries and eng/local-xharness/ before merging. -->
+    <add key="local-xharness-pr-1597-linux" value="/__w/1/s/eng/local-xharness" />
+    <add key="local-xharness-pr-1597-windows" value="D:\a\1\s\eng\local-xharness" />
     <add key="dotnet-public" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-public/nuget/v3/index.json" />
     <add key="dotnet-tools" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-tools/nuget/v3/index.json" />
     <add key="dotnet-eng" value="https://pkgs.dev.azure.com/dnceng/public/_packaging/dotnet-eng/nuget/v3/index.json" />
diff --git a/eng/Version.Details.props b/eng/Version.Details.props
index fe4350869d17a8..1553ef91e8c33f 100644
--- a/eng/Version.Details.props
+++ b/eng/Version.Details.props
@@ -114,9 +114,9 @@ This file should be imported by eng/Versions.props
     <SystemTextRegularExpressionsTestDataPackageVersion>11.0.0-beta.26302.1</SystemTextRegularExpressionsTestDataPackageVersion>
     <SystemWindowsExtensionsTestDataPackageVersion>11.0.0-beta.26302.1</SystemWindowsExtensionsTestDataPackageVersion>
     <!-- dotnet-xharness dependencies -->
-    <MicrosoftDotNetXHarnessCLIPackageVersion>11.0.0-prerelease.26279.1</MicrosoftDotNetXHarnessCLIPackageVersion>
-    <MicrosoftDotNetXHarnessTestRunnersCommonPackageVersion>11.0.0-prerelease.26279.1</MicrosoftDotNetXHarnessTestRunnersCommonPackageVersion>
-    <MicrosoftDotNetXHarnessTestRunnersXunitPackageVersion>11.0.0-prerelease.26279.1</MicrosoftDotNetXHarnessTestRunnersXunitPackageVersion>
+    <MicrosoftDotNetXHarnessCLIPackageVersion>11.0.0-prerelease.26308.1</MicrosoftDotNetXHarnessCLIPackageVersion>
+    <MicrosoftDotNetXHarnessTestRunnersCommonPackageVersion>11.0.0-prerelease.26308.1</MicrosoftDotNetXHarnessTestRunnersCommonPackageVersion>
+    <MicrosoftDotNetXHarnessTestRunnersXunitPackageVersion>11.0.0-prerelease.26308.1</MicrosoftDotNetXHarnessTestRunnersXunitPackageVersion>
   </PropertyGroup>
   <!--Property group for alternate package version names-->
   <PropertyGroup>
diff --git a/eng/Version.Details.xml b/eng/Version.Details.xml
index ec0b7ad4b1beef..fb6f1cf3c7f8ff 100644
--- a/eng/Version.Details.xml
+++ b/eng/Version.Details.xml
@@ -287,17 +287,17 @@
       <Uri>https://github.com/dotnet/dotnet</Uri>
       <Sha>0eae08ed2f094f44e0151e4815e7cdd1a334fcdf</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.XHarness.TestRunners.Common" Version="11.0.0-prerelease.26279.1">
+    <Dependency Name="Microsoft.DotNet.XHarness.TestRunners.Common" Version="11.0.0-prerelease.26308.1">
       <Uri>https://github.com/dotnet/xharness</Uri>
-      <Sha>2cee83bf4841d72c9734a343f3003aeabdd46edf</Sha>
+      <Sha>1b5c7a70e84e1122165bc923252be1fe536a5c1f</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.XHarness.TestRunners.Xunit" Version="11.0.0-prerelease.26279.1">
+    <Dependency Name="Microsoft.DotNet.XHarness.TestRunners.Xunit" Version="11.0.0-prerelease.26308.1">
       <Uri>https://github.com/dotnet/xharness</Uri>
-      <Sha>2cee83bf4841d72c9734a343f3003aeabdd46edf</Sha>
+      <Sha>1b5c7a70e84e1122165bc923252be1fe536a5c1f</Sha>
     </Dependency>
-    <Dependency Name="Microsoft.DotNet.XHarness.CLI" Version="11.0.0-prerelease.26279.1">
+    <Dependency Name="Microsoft.DotNet.XHarness.CLI" Version="11.0.0-prerelease.26308.1">
       <Uri>https://github.com/dotnet/xharness</Uri>
-      <Sha>2cee83bf4841d72c9734a343f3003aeabdd46edf</Sha>
+      <Sha>1b5c7a70e84e1122165bc923252be1fe536a5c1f</Sha>
     </Dependency>
     <Dependency Name="Microsoft.DotNet.PackageTesting" Version="11.0.0-beta.26257.113">
       <Uri>https://github.com/dotnet/dotnet</Uri>
diff --git a/eng/local-xharness/.gitignore b/eng/local-xharness/.gitignore
new file mode 100644
index 00000000000000..0b337c9fd3f5d5
--- /dev/null
+++ b/eng/local-xharness/.gitignore
@@ -0,0 +1,3 @@
+# Override the repo-wide *.nupkg ignore for this folder so the local feed
+# nupkgs for the dotnet/xharness PR #1597 validation can be committed.
+!*.nupkg
diff --git a/eng/local-xharness/Microsoft.DotNet.XHarness.CLI.11.0.0-prerelease.26308.1.nupkg b/eng/local-xharness/Microsoft.DotNet.XHarness.CLI.11.0.0-prerelease.26308.1.nupkg
new file mode 100644
index 00000000000000..169871cb998bac
Binary files /dev/null and b/eng/local-xharness/Microsoft.DotNet.XHarness.CLI.11.0.0-prerelease.26308.1.nupkg differ
diff --git a/eng/local-xharness/Microsoft.DotNet.XHarness.Common.11.0.0-prerelease.26308.1.nupkg b/eng/local-xharness/Microsoft.DotNet.XHarness.Common.11.0.0-prerelease.26308.1.nupkg
new file mode 100644
index 00000000000000..971393970271c9
Binary files /dev/null and b/eng/local-xharness/Microsoft.DotNet.XHarness.Common.11.0.0-prerelease.26308.1.nupkg differ
diff --git a/eng/local-xharness/Microsoft.DotNet.XHarness.DefaultAndroidEntryPoint.Xunit.11.0.0-prerelease.26308.1.nupkg b/eng/local-xharness/Microsoft.DotNet.XHarness.DefaultAndroidEntryPoint.Xunit.11.0.0-prerelease.26308.1.nupkg
new file mode 100644
index 00000000000000..e4cb770e762751
Binary files /dev/null and b/eng/local-xharness/Microsoft.DotNet.XHarness.DefaultAndroidEntryPoint.Xunit.11.0.0-prerelease.26308.1.nupkg differ
diff --git a/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.Common.11.0.0-prerelease.26308.1.nupkg b/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.Common.11.0.0-prerelease.26308.1.nupkg
new file mode 100644
index 00000000000000..07a32652047cda
Binary files /dev/null and b/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.Common.11.0.0-prerelease.26308.1.nupkg differ
diff --git a/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.NUnit.11.0.0-prerelease.26308.1.nupkg b/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.NUnit.11.0.0-prerelease.26308.1.nupkg
new file mode 100644
index 00000000000000..ce9e3ed092fac2
Binary files /dev/null and b/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.NUnit.11.0.0-prerelease.26308.1.nupkg differ
diff --git a/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.Xunit.11.0.0-prerelease.26308.1.nupkg b/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.Xunit.11.0.0-prerelease.26308.1.nupkg
new file mode 100644
index 00000000000000..7f427f9a185470
Binary files /dev/null and b/eng/local-xharness/Microsoft.DotNet.XHarness.TestRunners.Xunit.11.0.0-prerelease.26308.1.nupkg differ
diff --git a/eng/local-xharness/Microsoft.DotNet.XHarness.iOS.Shared.11.0.0-prerelease.26308.1.nupkg b/eng/local-xharness/Microsoft.DotNet.XHarness.iOS.Shared.11.0.0-prerelease.26308.1.nupkg
new file mode 100644
index 00000000000000..9d06643333baef
Binary files /dev/null and b/eng/local-xharness/Microsoft.DotNet.XHarness.iOS.Shared.11.0.0-prerelease.26308.1.nupkg differ