diff --git a/src/Test/L0/Worker/HandlerFactoryL0.cs b/src/Test/L0/Worker/HandlerFactoryL0.cs
index 4cfb70bc5..ea0c6ef46 100644
--- a/src/Test/L0/Worker/HandlerFactoryL0.cs
+++ b/src/Test/L0/Worker/HandlerFactoryL0.cs
@@ -317,5 +317,109 @@ namespace GitHub.Runner.Common.Tests.Worker
                 Assert.Contains("some-org/old-action@v1", deprecatedActions);
             }
         }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void Node20Action_WithSubpath_TrackedCorrectly()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange.
+                var hf = new HandlerFactory();
+                hf.Initialize(hc);
+
+                var variables = new Dictionary<string, VariableValue>
+                {
+                    { Constants.Runner.NodeMigration.WarnOnNode20Flag, new VariableValue("true") }
+                };
+                Variables serverVariables = new(hc, variables);
+                var deprecatedActions = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                _ec.Setup(x => x.Global).Returns(new GlobalContext()
+                {
+                    Variables = serverVariables,
+                    EnvironmentVariables = new Dictionary<string, string>(),
+                    DeprecatedNode20Actions = deprecatedActions
+                });
+
+                var actionRef = new RepositoryPathReference
+                {
+                    Name = "some-org/monorepo",
+                    Path = "actions/my-action",
+                    Ref = "v2"
+                };
+
+                // Act.
+                var data = new NodeJSActionExecutionData();
+                data.NodeVersion = "node20";
+                hf.Create(
+                    _ec.Object,
+                    actionRef,
+                    new Mock<IStepHost>().Object,
+                    data,
+                    new Dictionary<string, string>(),
+                    new Dictionary<string, string>(),
+                    new Variables(hc, new Dictionary<string, VariableValue>()),
+                    "",
+                    new List<JobExtensionRunner>()
+                );
+
+                // Assert - subpath should be included in tracked name
+                Assert.Contains("some-org/monorepo/actions/my-action@v2", deprecatedActions);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public void Node20Action_SanitizesNewlinesInActionName()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                // Arrange.
+                var hf = new HandlerFactory();
+                hf.Initialize(hc);
+
+                var variables = new Dictionary<string, VariableValue>
+                {
+                    { Constants.Runner.NodeMigration.WarnOnNode20Flag, new VariableValue("true") }
+                };
+                Variables serverVariables = new(hc, variables);
+                var deprecatedActions = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
+
+                _ec.Setup(x => x.Global).Returns(new GlobalContext()
+                {
+                    Variables = serverVariables,
+                    EnvironmentVariables = new Dictionary<string, string>(),
+                    DeprecatedNode20Actions = deprecatedActions
+                });
+
+                var actionRef = new RepositoryPathReference
+                {
+                    Name = "evil-org/bad\r\naction",
+                    Ref = "v1"
+                };
+
+                // Act.
+                var data = new NodeJSActionExecutionData();
+                data.NodeVersion = "node20";
+                hf.Create(
+                    _ec.Object,
+                    actionRef,
+                    new Mock<IStepHost>().Object,
+                    data,
+                    new Dictionary<string, string>(),
+                    new Dictionary<string, string>(),
+                    new Variables(hc, new Dictionary<string, VariableValue>()),
+                    "",
+                    new List<JobExtensionRunner>()
+                );
+
+                // Assert - CR/LF should be stripped to prevent log/annotation injection
+                Assert.Contains("evil-org/badaction@v1", deprecatedActions);
+                Assert.DoesNotContain("evil-org/bad\r\naction@v1", deprecatedActions);
+            }
+        }
     }
 }
diff --git a/src/Test/L0/Worker/JobExtensionL0.cs b/src/Test/L0/Worker/JobExtensionL0.cs
index 60814998e..d9954e259 100644
--- a/src/Test/L0/Worker/JobExtensionL0.cs
+++ b/src/Test/L0/Worker/JobExtensionL0.cs
@@ -755,5 +755,113 @@ namespace GitHub.Runner.Common.Tests.Worker
             Environment.SetEnvironmentVariable("RUNNER_ENVIRONMENT", null);
             Environment.SetEnvironmentVariable("GITHUB_ACTIONS_IMAGE_GEN_ENABLED", null);
         }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public async Task FinalizeJob_EmitsDeprecationWarning_WhenNode20ActionsExist()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                var jobExtension = new JobExtension();
+                jobExtension.Initialize(hc);
+
+                _jobEc = new Runner.Worker.ExecutionContext { Result = TaskResult.Succeeded };
+                _jobEc.Initialize(hc);
+                _jobEc.InitializeJob(_message, _tokenSource.Token);
+
+                // Add deprecated actions
+                _jobEc.Global.DeprecatedNode20Actions.Add("actions/checkout@v4");
+                _jobEc.Global.DeprecatedNode20Actions.Add("actions/setup-node@v3");
+
+                await jobExtension.FinalizeJob(_jobEc, _message, DateTime.UtcNow);
+
+                // Verify warning was written to log containing the action names
+                _logger.Verify(x => x.Write(It.Is<string>(s =>
+                    s.Contains("actions/checkout@v4") &&
+                    s.Contains("actions/setup-node@v3") &&
+                    s.Contains("Node.js 20 is approaching end-of-life"))), Times.AtLeastOnce);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public async Task FinalizeJob_NoDeprecationWarning_WhenNoNode20Actions()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                var jobExtension = new JobExtension();
+                jobExtension.Initialize(hc);
+
+                _jobEc = new Runner.Worker.ExecutionContext { Result = TaskResult.Succeeded };
+                _jobEc.Initialize(hc);
+                _jobEc.InitializeJob(_message, _tokenSource.Token);
+
+                // DeprecatedNode20Actions is initialized but empty
+                Assert.Empty(_jobEc.Global.DeprecatedNode20Actions);
+
+                await jobExtension.FinalizeJob(_jobEc, _message, DateTime.UtcNow);
+
+                // Verify no deprecation warning was emitted
+                _logger.Verify(x => x.Write(It.Is<string>(s =>
+                    s.Contains("Node.js 20 is approaching end-of-life"))), Times.Never);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public async Task FinalizeJob_TruncatesActionsListAtTen()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                var jobExtension = new JobExtension();
+                jobExtension.Initialize(hc);
+
+                _jobEc = new Runner.Worker.ExecutionContext { Result = TaskResult.Succeeded };
+                _jobEc.Initialize(hc);
+                _jobEc.InitializeJob(_message, _tokenSource.Token);
+
+                // Add 15 deprecated actions
+                for (int i = 1; i <= 15; i++)
+                {
+                    _jobEc.Global.DeprecatedNode20Actions.Add($"org/action-{i:D2}@v1");
+                }
+
+                await jobExtension.FinalizeJob(_jobEc, _message, DateTime.UtcNow);
+
+                // Verify truncation message appears with correct count
+                _logger.Verify(x => x.Write(It.Is<string>(s =>
+                    s.Contains("... and 5 more"))), Times.AtLeastOnce);
+            }
+        }
+
+        [Fact]
+        [Trait("Level", "L0")]
+        [Trait("Category", "Worker")]
+        public async Task FinalizeJob_SortsActionsAlphabetically()
+        {
+            using (TestHostContext hc = CreateTestContext())
+            {
+                var jobExtension = new JobExtension();
+                jobExtension.Initialize(hc);
+
+                _jobEc = new Runner.Worker.ExecutionContext { Result = TaskResult.Succeeded };
+                _jobEc.Initialize(hc);
+                _jobEc.InitializeJob(_message, _tokenSource.Token);
+
+                // Add actions in reverse alphabetical order
+                _jobEc.Global.DeprecatedNode20Actions.Add("z-org/last-action@v1");
+                _jobEc.Global.DeprecatedNode20Actions.Add("a-org/first-action@v1");
+                _jobEc.Global.DeprecatedNode20Actions.Add("m-org/middle-action@v1");
+
+                await jobExtension.FinalizeJob(_jobEc, _message, DateTime.UtcNow);
+
+                // Verify actions appear sorted: a-org before m-org before z-org
+                _logger.Verify(x => x.Write(It.Is<string>(s =>
+                    s.Contains("a-org/first-action@v1, m-org/middle-action@v1, z-org/last-action@v1"))), Times.AtLeastOnce);
+            }
+        }
     }
 }