diff --git a/azure-pipelines/vmr-sb-validation.yml b/azure-pipelines/vmr-sb-validation.yml
index dbbac51897b..f60df5fa050 100644
--- a/azure-pipelines/vmr-sb-validation.yml
+++ b/azure-pipelines/vmr-sb-validation.yml
@@ -29,7 +29,7 @@ resources:
   - repository: vmr
     type: github
     name: dotnet/dotnet
-    endpoint: dotnet
+    endpoint: public
 
 stages:
 - template: /eng/pipelines/templates/stages/vmr-build.yml@vmr
diff --git a/eng/Versions.props b/eng/Versions.props
index 4a7d92089b8..e4f9bbfb7b6 100644
--- a/eng/Versions.props
+++ b/eng/Versions.props
@@ -3,7 +3,7 @@
   <Import Project="Version.Details.props" />
 
   <PropertyGroup>
-    <VersionPrefix>18.7.11</VersionPrefix><DotNetFinalVersionKind>release</DotNetFinalVersionKind><!-- Keep next to VersionPrefix to create a conflict in forward-flow -->
+    <VersionPrefix>18.7.12</VersionPrefix><DotNetFinalVersionKind>release</DotNetFinalVersionKind><!-- Keep next to VersionPrefix to create a conflict in forward-flow -->
     <PreReleaseVersionLabel>servicing</PreReleaseVersionLabel>
     <PackageValidationBaselineVersion>18.6.0-preview-26180-08</PackageValidationBaselineVersion>
     <AssemblyVersion>15.1.0.0</AssemblyVersion>
diff --git a/src/Framework/NativeMethods.cs b/src/Framework/NativeMethods.cs
index cf1c317cee4..f935286d1c7 100644
--- a/src/Framework/NativeMethods.cs
+++ b/src/Framework/NativeMethods.cs
@@ -1496,15 +1496,18 @@ internal static List<KeyValuePair<int, SafeProcessHandle>> GetChildProcessIds(in
     /// Internal, optimized GetCurrentDirectory implementation that simply delegates to the native method
     /// </summary>
     /// <returns></returns>
-    internal static unsafe string GetCurrentDirectory()
+    internal static string GetCurrentDirectory()
     {
 #if FEATURE_LEGACY_GETCURRENTDIRECTORY
         if (IsWindows)
         {
-            int bufferSize = GetCurrentDirectoryWin32(0, null);
-            char* buffer = stackalloc char[bufferSize];
-            int pathLength = GetCurrentDirectoryWin32(bufferSize, buffer);
-            return new string(buffer, startIndex: 0, length: pathLength);
+            unsafe
+            {
+                int bufferSize = GetCurrentDirectoryWin32(0, null);
+                char* buffer = stackalloc char[bufferSize];
+                int pathLength = GetCurrentDirectoryWin32(bufferSize, buffer);
+                return new string(buffer, startIndex: 0, length: pathLength);
+            }
         }
 #endif
         return Directory.GetCurrentDirectory();
diff --git a/src/MSBuild.Bootstrap.Utils/Tasks/InstallDotNetCoreTask.cs b/src/MSBuild.Bootstrap.Utils/Tasks/InstallDotNetCoreTask.cs
index 9606b11002d..15d35446d8a 100644
--- a/src/MSBuild.Bootstrap.Utils/Tasks/InstallDotNetCoreTask.cs
+++ b/src/MSBuild.Bootstrap.Utils/Tasks/InstallDotNetCoreTask.cs
@@ -154,13 +154,32 @@ private ScriptExecutionSettings SetupScriptsExecutionSettings()
         {
             string scriptExtension = IsWindows ? "ps1" : "sh";
             string scriptPath = Path.Combine(DotNetInstallScriptRootPath, $"{ScriptName}.{scriptExtension}");
+            // On Windows the native command-line parser treats a backslash before the closing quote as
+            // escaping it (e.g. "C:\dir\" becomes C:\dir"), so trim a trailing separator before quoting.
+            string installDir = TrimTrailingDirectorySeparators(InstallDir);
             string scriptArgs = IsWindows
-                ? $"-NoProfile -ExecutionPolicy Bypass -File {scriptPath} -Version {Version} -InstallDir {InstallDir}"
-                : $"{scriptPath} --version {Version} --install-dir {InstallDir}";
+                ? $"-NoProfile -ExecutionPolicy Bypass -File \"{scriptPath}\" -Version {Version} -InstallDir \"{installDir}\""
+                : $"\"{scriptPath}\" --version {Version} --install-dir \"{installDir}\"";
 
             return new ScriptExecutionSettings($"{ScriptName}.{scriptExtension}", scriptPath, scriptArgs);
         }
 
+        /// <summary>
+        /// Trims trailing directory separators while preserving a path root (e.g. "C:\").
+        /// </summary>
+        private static string TrimTrailingDirectorySeparators(string path)
+        {
+            string root = Path.GetPathRoot(path) ?? string.Empty;
+            while (path.Length > root.Length &&
+                   (path[path.Length - 1] == Path.DirectorySeparatorChar ||
+                    path[path.Length - 1] == Path.AltDirectorySeparatorChar))
+            {
+                path = path.Substring(0, path.Length - 1);
+            }
+
+            return path;
+        }
+
         /// <summary>
         /// A private struct to hold settings for script execution.
         /// </summary>