diff --git a/src/Umbraco.Cms.Api.Management/Controllers/DocumentType/DocumentTypeControllerBase.cs b/src/Umbraco.Cms.Api.Management/Controllers/DocumentType/DocumentTypeControllerBase.cs
index 2fe34df7a1..4eb3dd2426 100644
--- a/src/Umbraco.Cms.Api.Management/Controllers/DocumentType/DocumentTypeControllerBase.cs
+++ b/src/Umbraco.Cms.Api.Management/Controllers/DocumentType/DocumentTypeControllerBase.cs
@@ -44,6 +44,10 @@ public abstract class DocumentTypeControllerBase : ManagementApiControllerBase
                     .WithTitle("Invalid container name")
                     .WithDetail("One or more container names are invalid")
                     .Build()),
+                ContentTypeOperationStatus.InvalidContainerType => new BadRequestObjectResult(problemDetailsBuilder
+                    .WithTitle("Invalid container type")
+                    .WithDetail("One or more container types are invalid")
+                    .Build()),
                 ContentTypeOperationStatus.MissingContainer => new BadRequestObjectResult(problemDetailsBuilder
                     .WithTitle("Missing container")
                     .WithDetail("One or more containers or properties are listed as parents to containers that are not defined.")
diff --git a/src/Umbraco.Core/Services/ContentTypeEditing/ContentTypeEditingServiceBase.cs b/src/Umbraco.Core/Services/ContentTypeEditing/ContentTypeEditingServiceBase.cs
index 0940b693ff..80a574537f 100644
--- a/src/Umbraco.Core/Services/ContentTypeEditing/ContentTypeEditingServiceBase.cs
+++ b/src/Umbraco.Core/Services/ContentTypeEditing/ContentTypeEditingServiceBase.cs
@@ -343,6 +343,11 @@ internal abstract class ContentTypeEditingServiceBase<TContentType, TContentType
 
     private ContentTypeOperationStatus ValidateContainers(ContentTypeEditingModelBase<TPropertyTypeModel, TPropertyTypeContainer> model, IContentTypeComposition[] allContentTypeCompositions)
     {
+        if (model.Containers.Any(container => Enum.TryParse<PropertyGroupType>(container.Type, out _) is false))
+        {
+            return ContentTypeOperationStatus.InvalidContainerType;
+        }
+
         // all property container keys must be present in the model
         Guid[] modelContainerKeys = model.Containers.Select(c => c.Key).ToArray();
         if (model.Properties.Any(p => p.ContainerKey is not null && modelContainerKeys.Contains(p.ContainerKey.Value) is false))
diff --git a/src/Umbraco.Core/Services/OperationStatus/ContentTypeOperationStatus.cs b/src/Umbraco.Core/Services/OperationStatus/ContentTypeOperationStatus.cs
index 86a32f7fc8..9f9c46e874 100644
--- a/src/Umbraco.Core/Services/OperationStatus/ContentTypeOperationStatus.cs
+++ b/src/Umbraco.Core/Services/OperationStatus/ContentTypeOperationStatus.cs
@@ -12,6 +12,7 @@ public enum ContentTypeOperationStatus
     InvalidComposition,
     InvalidParent,
     InvalidContainerName,
+    InvalidContainerType,
     MissingContainer,
     DuplicateContainer,
     NotFound,
diff --git a/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/ContentTypeEditingServiceTests.Create.cs b/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/ContentTypeEditingServiceTests.Create.cs
index 28dd1f5b0b..2e261015e2 100644
--- a/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/ContentTypeEditingServiceTests.Create.cs
+++ b/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/ContentTypeEditingServiceTests.Create.cs
@@ -1086,4 +1086,21 @@ public partial class ContentTypeEditingServiceTests
         Assert.IsFalse(result.Success);
         Assert.AreEqual(ContentTypeOperationStatus.InvalidComposition, result.Status);
     }
+
+    [TestCase("something")]
+    [TestCase("tab")]
+    [TestCase("group")]
+    public async Task Cannot_Create_Container_With_Unknown_Type(string containerType)
+    {
+        var createModel = ContentTypeCreateModel("Test", "test");
+        var container = ContentTypePropertyContainerModel(name: containerType, type: containerType);
+        createModel.Containers = new[] { container };
+
+        var propertyType = ContentTypePropertyTypeModel("Test Property", "testProperty", containerKey: container.Key);
+        createModel.Properties = new[] { propertyType };
+
+        var result = await ContentTypeEditingService.CreateAsync(createModel, Constants.Security.SuperUserKey);
+        Assert.IsFalse(result.Success);
+        Assert.AreEqual(ContentTypeOperationStatus.InvalidContainerType, result.Status);
+    }
 }
diff --git a/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/ContentTypeEditingServiceTests.Update.cs b/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/ContentTypeEditingServiceTests.Update.cs
index f705f2732f..31be783629 100644
--- a/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/ContentTypeEditingServiceTests.Update.cs
+++ b/tests/Umbraco.Tests.Integration/Umbraco.Core/Services/ContentTypeEditingServiceTests.Update.cs
@@ -802,4 +802,28 @@ public partial class ContentTypeEditingServiceTests
         Assert.IsFalse(result.Success);
         Assert.AreEqual(ContentTypeOperationStatus.InvalidInheritance, result.Status);
     }
+
+    [TestCase("something")]
+    [TestCase("tab")]
+    [TestCase("group")]
+    public async Task Cannot_Update_Container_Types_To_Unknown_Types(string containerType)
+    {
+        var createModel = ContentTypeCreateModel("Test", "test");
+        var container = ContentTypePropertyContainerModel("One");
+        createModel.Containers = new[] { container };
+
+        var property = ContentTypePropertyTypeModel("Test Property", "testProperty", containerKey: container.Key);
+        createModel.Properties = new[] { property };
+
+        var contentType = (await ContentTypeEditingService.CreateAsync(createModel, Constants.Security.SuperUserKey)).Result!;
+
+        var updateModel = ContentTypeUpdateModel("Test", "test");
+        container.Type = containerType;
+        updateModel.Containers = new[] { container };
+        updateModel.Properties = new[] { property };
+
+        var result = await ContentTypeEditingService.UpdateAsync(contentType, updateModel, Constants.Security.SuperUserKey);
+        Assert.IsFalse(result.Success);
+        Assert.AreEqual(ContentTypeOperationStatus.InvalidContainerType, result.Status);
+    }
 }