diff --git a/.azure-pipelines/build-job.yml b/.azure-pipelines/build-job.yml
index 02c5233de2..1ac3ebb543 100644
--- a/.azure-pipelines/build-job.yml
+++ b/.azure-pipelines/build-job.yml
@@ -88,6 +88,8 @@ jobs:
           targetFramework: 'net6.0'
         NET8.0:
           targetFramework: 'net8.0'
+        NET9.0:
+          targetFramework: 'net9.0'
 
 
   ${{ if ne(parameters.container, '') }}:
diff --git a/.azure-pipelines/pipeline.yml b/.azure-pipelines/pipeline.yml
index cdb2d004ce..814f5dbd52 100644
--- a/.azure-pipelines/pipeline.yml
+++ b/.azure-pipelines/pipeline.yml
@@ -112,6 +112,8 @@ extends:
                   targetFramework: 'net6.0'
                 NET8.0:
                   targetFramework: 'net8.0'
+                NET9.0:
+                  targetFramework: 'net9.0'
           pool:
               name: 1ES-ABTT-Shared-Pool
               image: abtt-ubuntu-2204
diff --git a/.vsts.release.yml b/.vsts.release.yml
index 396141213c..117c98b0d5 100644
--- a/.vsts.release.yml
+++ b/.vsts.release.yml
@@ -38,6 +38,7 @@ parameters:
   values:
   - net6.0
   - net8.0
+  - net9.0
 - name: derivedFrom
   type: string
   displayName: Derived From Version
@@ -149,9 +150,14 @@ extends:
 
                 ## Verify target framework for specified version
                 $majorVersion = $agentVersion.Split('.')[0]
-                if (("${{ parameters.targetFramework }}" -eq "net6.0" -and $majorVersion -ne "3") -or
-                   ("${{ parameters.targetFramework }}" -eq "net8.0" -and $majorVersion -ne "4")) {
-                  Write-Error "The major version should be 3 for net6.0 and 4 for net8.0" -ErrorAction Stop
+                if (
+                  ("${{ parameters.targetFramework }}" -eq "net6.0" -and $majorVersion -ne "3") -or
+                  (
+                    ("${{ parameters.targetFramework }}" -eq "net8.0" -and $majorVersion -ne "4") -or
+                    ("${{ parameters.targetFramework }}" -eq "net9.0" -and $majorVersion -ne "4")
+                  )
+                ) {
+                  Write-Error "The major version should be 3 for net6.0 and 4 for net8.0 or net9.0" -ErrorAction Stop
                 }
               }
               if ($isTestRun) {
diff --git a/src/Agent.Plugins/TFCliManager.cs b/src/Agent.Plugins/TFCliManager.cs
index cd9032967f..4ecfcd6a31 100644
--- a/src/Agent.Plugins/TFCliManager.cs
+++ b/src/Agent.Plugins/TFCliManager.cs
@@ -162,7 +162,9 @@ public void SetupProxy(string proxyUrl, string proxyUsername, string proxyPasswo
         public void SetupClientCertificate(string clientCert, string clientCertKey, string clientCertArchive, string clientCertPassword)
         {
             ArgUtil.File(clientCert, nameof(clientCert));
+            #pragma warning disable SYSLIB0057
             X509Certificate2 cert = new X509Certificate2(clientCert);
+            #pragma warning restore SYSLIB0057
             ExecutionContext.Debug($"Set VstsClientCertificate={cert.Thumbprint} for Tf.exe to support client certificate.");
             AdditionalEnvironmentVariables["VstsClientCertificate"] = cert.Thumbprint;
 
diff --git a/src/Agent.Sdk/AgentClientCertificateManager.cs b/src/Agent.Sdk/AgentClientCertificateManager.cs
index 22a585201b..04ec6dad1b 100644
--- a/src/Agent.Sdk/AgentClientCertificateManager.cs
+++ b/src/Agent.Sdk/AgentClientCertificateManager.cs
@@ -35,7 +35,9 @@ public void AddClientCertificate(string clientCertificateArchiveFile, string cli
         {
             if (!string.IsNullOrEmpty(clientCertificateArchiveFile))
             {
+                #pragma warning disable SYSLIB0057
                 _clientCertificates.Add(new X509Certificate2(clientCertificateArchiveFile, clientCertificatePassword));
+                #pragma warning restore SYSLIB0057
             }
         }
     }
diff --git a/src/Agent.Worker/Build/TFCommandManager.cs b/src/Agent.Worker/Build/TFCommandManager.cs
index f44f9fdbbe..8ac45ab747 100644
--- a/src/Agent.Worker/Build/TFCommandManager.cs
+++ b/src/Agent.Worker/Build/TFCommandManager.cs
@@ -159,7 +159,9 @@ public void SetupProxy(string proxyUrl, string proxyUsername, string proxyPasswo
         public void SetupClientCertificate(string clientCert, string clientCertKey, string clientCertArchive, string clientCertPassword)
         {
             ArgUtil.File(clientCert, nameof(clientCert));
+            #pragma warning disable SYSLIB0057
             X509Certificate2 cert = new X509Certificate2(clientCert);
+            #pragma warning restore SYSLIB0057
             ExecutionContext.Debug($"Set VstsClientCertificate={cert.Thumbprint} for Tf.exe to support client certificate.");
             AdditionalEnvironmentVariables["VstsClientCertificate"] = cert.Thumbprint;
 
diff --git a/src/Common.props b/src/Common.props
index 8b1b645a91..acf2909500 100644
--- a/src/Common.props
+++ b/src/Common.props
@@ -1,7 +1,7 @@
 <Project>
   <PropertyGroup>
     <LangVersion>10.0</LangVersion>
-    <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net6.0;net8.0;net9.0</TargetFrameworks>
     <RuntimeIdentifier Condition="'$(BuildingInsideVisualStudio)' != 'true'">$(PackageRuntime)</RuntimeIdentifier>
     <SelfContained>true</SelfContained>
     <TargetLatestRuntimePatch>true</TargetLatestRuntimePatch>
diff --git a/src/dev.sh b/src/dev.sh
index d292ac5106..b6907c06a7 100755
--- a/src/dev.sh
+++ b/src/dev.sh
@@ -47,12 +47,15 @@ function get_net_version() {
 
         net8.0-sdk=8.0.401
         net8.0-runtime=8.0.8
+
+        net9.0-sdk=9.0.100
+        net9.0-runtime=9.0.0
     "
 
     echo "$dotnet_versions" | grep -o "$1=[^ ]*" | cut -d '=' -f2
 }
 
-DOTNET_SDK_VERSION=$(get_net_version "net8.0-sdk")
+DOTNET_SDK_VERSION=$(get_net_version "${TARGET_FRAMEWORK}-sdk")
 DOTNET_RUNTIME_VERSION=$(get_net_version "${TARGET_FRAMEWORK}-runtime")
 
 if [[ ($DOTNET_SDK_VERSION == "") || ($DOTNET_RUNTIME_VERSION == "") ]]; then