From 0816a2f5e507a5f809dfe7592138c0bd7c13cc17 Mon Sep 17 00:00:00 2001
From: Mateusz Kiersnowski <mateusz.kiersnowski@gmail.com>
Date: Wed, 22 Oct 2025 20:47:54 +0200
Subject: [PATCH 1/5] Add test for creating a CloudFormation stack from a
 template

---
 .../cloudformation/api/test_stacks.py         | 23 +++++
 .../api/test_stacks.snapshot.json             | 93 ++++++-------------
 tests/aws/templates/ec2_cfn_init_template.yml | 67 +++++++++++++
 3 files changed, 116 insertions(+), 67 deletions(-)
 create mode 100644 tests/aws/templates/ec2_cfn_init_template.yml

diff --git a/tests/aws/services/cloudformation/api/test_stacks.py b/tests/aws/services/cloudformation/api/test_stacks.py
index dc70b77aafca9..cb9969e8f89bd 100644
--- a/tests/aws/services/cloudformation/api/test_stacks.py
+++ b/tests/aws/services/cloudformation/api/test_stacks.py
@@ -183,6 +183,29 @@ def test_stack_name_creation(self, deploy_cfn_template, snapshot, aws_client):
 
             snapshot.match("stack_response", e.value.response)
 
+    @markers.aws.only_localstack
+    def test_create_stack_from_template(self, snapshot, aws_client):
+        snapshot.add_transformer(snapshot.transform.cloudformation_api())
+
+        stack_name = f"stack-{short_uid()}"
+
+        result = aws_client.cloudformation.create_stack(
+            StackName=stack_name,
+            TemplateBody=load_file(
+                os.path.join(
+                    os.path.dirname(__file__), "../../../templates/ec2_cfn_init_template.yml"
+                )
+            ),
+        )
+        snapshot.match("stack_create_ec2", result)
+
+        aws_client.cloudformation.get_waiter("stack_create_complete").wait(StackName=stack_name)
+
+        describe_result = aws_client.cloudformation.describe_stacks(StackName=stack_name)
+        snapshot.match("stack_description", describe_result)
+
+        aws_client.cloudformation.delete_stack(StackName=stack_name)
+
     @markers.aws.validated
     @pytest.mark.parametrize("fileformat", ["yaml", "json"])
     def test_get_template_using_create_stack(self, snapshot, fileformat, aws_client):
diff --git a/tests/aws/services/cloudformation/api/test_stacks.snapshot.json b/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
index fde3beada5d45..9218ae6c3d4ab 100644
--- a/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
+++ b/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
@@ -4205,8 +4205,8 @@
       ]
     }
   },
-  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_stack_description_lifecycle[no-tags]": {
-    "recorded-date": "09-09-2025, 09:37:20",
+  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_stack_description_lifecycle": {
+    "recorded-date": "08-08-2025, 15:30:34",
     "recorded-content": {
       "change-set-pre-execute": {
         "Capabilities": [],
@@ -4271,80 +4271,39 @@
       }
     }
   },
-  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_stack_description_lifecycle[with-tags]": {
-    "recorded-date": "09-09-2025, 09:37:28",
+  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_create_stack_from_template": {
+    "recorded-date": "22-10-2025, 18:44:36",
     "recorded-content": {
-      "change-set-pre-execute": {
-        "Capabilities": [],
-        "ChangeSetId": "arn:<partition>:cloudformation:<region>:111111111111:changeSet/<resource:1>",
-        "ChangeSetName": "<change-set-name:1>",
-        "Changes": [
+      "stack_create_ec2": {
+        "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:1>",
+        "ResponseMetadata": {
+          "HTTPHeaders": {},
+          "HTTPStatusCode": 200
+        }
+      },
+      "stack_description": {
+        "Stacks": [
           {
-            "ResourceChange": {
-              "Action": "Add",
-              "Details": [],
-              "LogicalResourceId": "TestResource",
-              "ResourceType": "AWS::SSM::Parameter",
-              "Scope": []
+            "CreationTime": "datetime",
+            "Description": "AWS CloudFormation sample template.  \nCreate an Amazon EC2 instance with cfn-init and cfn-signal.\n",
+            "DisableRollback": false,
+            "DriftInformation": {
+              "StackDriftStatus": "NOT_CHECKED"
             },
-            "Type": "Resource"
-          }
-        ],
-        "CreationTime": "datetime",
-        "ExecutionStatus": "AVAILABLE",
-        "IncludeNestedStacks": false,
-        "NotificationARNs": [],
-        "RollbackConfiguration": {},
-        "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:2>",
-        "StackName": "<stack-name:1>",
-        "Status": "CREATE_COMPLETE",
-        "Tags": [
-          {
-            "Key": "foo",
-            "Value": "bar"
+            "EnableTerminationProtection": false,
+            "LastUpdatedTime": "datetime",
+            "NotificationARNs": [],
+            "RollbackConfiguration": {},
+            "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:1>",
+            "StackName": "<stack-name:1>",
+            "StackStatus": "CREATE_COMPLETE",
+            "Tags": []
           }
         ],
         "ResponseMetadata": {
           "HTTPHeaders": {},
           "HTTPStatusCode": 200
         }
-      },
-      "stack-pre-execute": {
-        "CreationTime": "datetime",
-        "DisableRollback": false,
-        "DriftInformation": {
-          "StackDriftStatus": "NOT_CHECKED"
-        },
-        "EnableTerminationProtection": false,
-        "NotificationARNs": [],
-        "RollbackConfiguration": {},
-        "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:2>",
-        "StackName": "<stack-name:1>",
-        "StackStatus": "REVIEW_IN_PROGRESS",
-        "StackStatusReason": "User Initiated",
-        "Tags": []
-      },
-      "stack-post-execute": {
-        "ChangeSetId": "arn:<partition>:cloudformation:<region>:111111111111:changeSet/<resource:1>",
-        "CreationTime": "datetime",
-        "Description": "test <env>.test.net",
-        "DisableRollback": false,
-        "DriftInformation": {
-          "StackDriftStatus": "NOT_CHECKED"
-        },
-        "EnableTerminationProtection": false,
-        "LastUpdatedTime": "datetime",
-        "NotificationARNs": [],
-        "RollbackConfiguration": {},
-        "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:2>",
-        "StackName": "<stack-name:1>",
-        "StackStatus": "CREATE_COMPLETE",
-        "Tags": [
-          {
-            "Key": "foo",
-            "Value": "bar"
-          }
-        ]
       }
     }
   }
diff --git a/tests/aws/templates/ec2_cfn_init_template.yml b/tests/aws/templates/ec2_cfn_init_template.yml
new file mode 100644
index 0000000000000..dce052b4ec7e7
--- /dev/null
+++ b/tests/aws/templates/ec2_cfn_init_template.yml
@@ -0,0 +1,67 @@
+AWSTemplateFormatVersion: "2010-09-09"
+
+Description: "AWS CloudFormation sample template.  \nCreate an Amazon EC2 instance with cfn-init and cfn-signal.\n"
+
+Resources:
+  Instance:
+    CreationPolicy:
+      ResourceSignal:
+        Timeout: PT5M
+    Type: AWS::EC2::Instance
+    Metadata:
+      guard:
+        SuppressedRules:
+          - EC2_INSTANCES_IN_VPC
+      AWS::CloudFormation::Init:
+        config:
+          packages:
+            yum:
+              httpd: []
+          files:
+            /var/www/html/index.html:
+              content: |
+                <body>
+                  <h1>Congratulations, you have successfully launched the AWS CloudFormation sample.</h1>
+                </body>
+              mode: "000644"
+              owner: root
+              group: root
+            /etc/cfn/cfn-hup.conf:
+              content: !Sub |
+                [main]
+                stack=${AWS::StackId}
+                region=${AWS::Region}
+              mode: "000400"
+              owner: root
+              group: root
+            /etc/cfn/hooks.d/cfn-auto-reloader.conf:
+              content: !Sub |-
+                [cfn-auto-reloader-hook]
+                triggers=post.update
+                path=Resources.LaunchConfig.Metadata.AWS::CloudFormation::Init
+                action=/opt/aws/bin/cfn-init -v --stack ${AWS::StackName} --resource Instance --region ${AWS::Region}
+                runas=root
+          services:
+            sysvinit:
+              httpd:
+                enabled: true
+                ensureRunning: true
+              cfn-hup:
+                enabled: true
+                ensureRunning: true
+                files:
+                  - /etc/cfn/cfn-hup.conf
+                  - /etc/cfn/hooks.d/cfn-auto-reloader.conf
+    Properties:
+      ImageId: '{{resolve:ssm:/aws/service/ami-amazon-linux-latest/al2023-ami-kernel-6.1-arm64}}'
+      InstanceType: t4g.nano
+      KeyName: sample
+      BlockDeviceMappings:
+        - DeviceName: /dev/sda1
+          Ebs:
+            VolumeSize: 32
+      UserData: !Base64
+        Fn::Sub: |-
+          #!/bin/bash
+          /opt/aws/bin/cfn-init -v --stack ${AWS::StackName} --resource Instance --region ${AWS::Region}
+          /opt/aws/bin/cfn-signal -e $? --stack ${AWS::StackName} --resource Instance --region ${AWS::Region}

From 0f237376a1f9fc1262b4470087895f2cd196219d Mon Sep 17 00:00:00 2001
From: Mateusz Kiersnowski <mateusz.kiersnowski@gmail.com>
Date: Thu, 23 Oct 2025 00:06:38 +0200
Subject: [PATCH 2/5] Fix snapshot after rebase

---
 .../api/test_stacks.snapshot.json             | 84 ++++++++++++++++++-
 1 file changed, 80 insertions(+), 4 deletions(-)

diff --git a/tests/aws/services/cloudformation/api/test_stacks.snapshot.json b/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
index 9218ae6c3d4ab..689e7bb61bf0c 100644
--- a/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
+++ b/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
@@ -4205,8 +4205,8 @@
       ]
     }
   },
-  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_stack_description_lifecycle": {
-    "recorded-date": "08-08-2025, 15:30:34",
+  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_stack_description_lifecycle[no-tags]": {
+    "recorded-date": "09-09-2025, 09:37:20",
     "recorded-content": {
       "change-set-pre-execute": {
         "Capabilities": [],
@@ -4271,8 +4271,85 @@
       }
     }
   },
+  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_stack_description_lifecycle[with-tags]": {
+    "recorded-date": "09-09-2025, 09:37:28",
+    "recorded-content": {
+      "change-set-pre-execute": {
+        "Capabilities": [],
+        "ChangeSetId": "arn:<partition>:cloudformation:<region>:111111111111:changeSet/<resource:1>",
+        "ChangeSetName": "<change-set-name:1>",
+        "Changes": [
+          {
+            "ResourceChange": {
+              "Action": "Add",
+              "Details": [],
+              "LogicalResourceId": "TestResource",
+              "ResourceType": "AWS::SSM::Parameter",
+              "Scope": []
+            },
+            "Type": "Resource"
+          }
+        ],
+        "CreationTime": "datetime",
+        "ExecutionStatus": "AVAILABLE",
+        "IncludeNestedStacks": false,
+        "NotificationARNs": [],
+        "RollbackConfiguration": {},
+        "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:2>",
+        "StackName": "<stack-name:1>",
+        "Status": "CREATE_COMPLETE",
+        "Tags": [
+          {
+            "Key": "foo",
+            "Value": "bar"
+          }
+        ],
+        "ResponseMetadata": {
+          "HTTPHeaders": {},
+          "HTTPStatusCode": 200
+        }
+      },
+      "stack-pre-execute": {
+        "CreationTime": "datetime",
+        "DisableRollback": false,
+        "DriftInformation": {
+          "StackDriftStatus": "NOT_CHECKED"
+        },
+        "EnableTerminationProtection": false,
+        "NotificationARNs": [],
+        "RollbackConfiguration": {},
+        "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:2>",
+        "StackName": "<stack-name:1>",
+        "StackStatus": "REVIEW_IN_PROGRESS",
+        "StackStatusReason": "User Initiated",
+        "Tags": []
+      },
+      "stack-post-execute": {
+        "ChangeSetId": "arn:<partition>:cloudformation:<region>:111111111111:changeSet/<resource:1>",
+        "CreationTime": "datetime",
+        "Description": "test <env>.test.net",
+        "DisableRollback": false,
+        "DriftInformation": {
+          "StackDriftStatus": "NOT_CHECKED"
+        },
+        "EnableTerminationProtection": false,
+        "LastUpdatedTime": "datetime",
+        "NotificationARNs": [],
+        "RollbackConfiguration": {},
+        "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:2>",
+        "StackName": "<stack-name:1>",
+        "StackStatus": "CREATE_COMPLETE",
+        "Tags": [
+          {
+            "Key": "foo",
+            "Value": "bar"
+          }
+        ]
+      }
+    }
+  },
   "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_create_stack_from_template": {
-    "recorded-date": "22-10-2025, 18:44:36",
+    "recorded-date": "22-10-2025, 22:04:58",
     "recorded-content": {
       "stack_create_ec2": {
         "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:1>",
@@ -4285,7 +4362,6 @@
         "Stacks": [
           {
             "CreationTime": "datetime",
-            "Description": "AWS CloudFormation sample template.  \nCreate an Amazon EC2 instance with cfn-init and cfn-signal.\n",
             "DisableRollback": false,
             "DriftInformation": {
               "StackDriftStatus": "NOT_CHECKED"

From 7d039037f64f1aa3594020d604353f09c9a3081d Mon Sep 17 00:00:00 2001
From: Mateusz Kiersnowski <mateusz.kiersnowski@gmail.com>
Date: Thu, 23 Oct 2025 21:15:22 +0200
Subject: [PATCH 3/5] handle invalid TemplateBody in create_stack cfn

---
 .../cloudformation/engine/yaml_parser.py      | 11 ++++--
 .../cloudformation/api/test_stacks.py         | 23 ++++--------
 .../api/test_stacks.snapshot.json             | 35 ++-----------------
 3 files changed, 18 insertions(+), 51 deletions(-)

diff --git a/localstack-core/localstack/services/cloudformation/engine/yaml_parser.py b/localstack-core/localstack/services/cloudformation/engine/yaml_parser.py
index c0b72ead58f8f..3d12004f42423 100644
--- a/localstack-core/localstack/services/cloudformation/engine/yaml_parser.py
+++ b/localstack-core/localstack/services/cloudformation/engine/yaml_parser.py
@@ -1,5 +1,7 @@
 import yaml
 
+from localstack.services.cloudformation.engine.validations import ValidationError
+
 
 def construct_raw(_, node):
     return node.value
@@ -60,5 +62,10 @@ def shorthand_constructor(loader: yaml.Loader, tag_suffix: str, node: yaml.Node)
 yaml.add_multi_constructor("!", shorthand_constructor, customloader)
 
 
-def parse_yaml(input_data: str):
-    return yaml.load(input_data, customloader)
+def parse_yaml(input_data: str) -> dict:
+    parsed = yaml.load(input_data, Loader=customloader)
+
+    if not isinstance(parsed, dict):
+        raise ValidationError("Template format error: unsupported structure.")
+
+    return parsed
diff --git a/tests/aws/services/cloudformation/api/test_stacks.py b/tests/aws/services/cloudformation/api/test_stacks.py
index cb9969e8f89bd..0189a32a9f607 100644
--- a/tests/aws/services/cloudformation/api/test_stacks.py
+++ b/tests/aws/services/cloudformation/api/test_stacks.py
@@ -183,28 +183,17 @@ def test_stack_name_creation(self, deploy_cfn_template, snapshot, aws_client):
 
             snapshot.match("stack_response", e.value.response)
 
-    @markers.aws.only_localstack
-    def test_create_stack_from_template(self, snapshot, aws_client):
+    @markers.aws.unknown
+    def test_create_stack_url_as_template(self, snapshot, aws_client):
         snapshot.add_transformer(snapshot.transform.cloudformation_api())
 
         stack_name = f"stack-{short_uid()}"
 
-        result = aws_client.cloudformation.create_stack(
-            StackName=stack_name,
-            TemplateBody=load_file(
-                os.path.join(
-                    os.path.dirname(__file__), "../../../templates/ec2_cfn_init_template.yml"
-                )
-            ),
-        )
-        snapshot.match("stack_create_ec2", result)
-
-        aws_client.cloudformation.get_waiter("stack_create_complete").wait(StackName=stack_name)
+        template_url = "https://raw.githubusercontent.com/aws-cloudformation/aws-cloudformation-templates/refs/heads/main/EC2/InstanceWithCfnInit.yaml"
 
-        describe_result = aws_client.cloudformation.describe_stacks(StackName=stack_name)
-        snapshot.match("stack_description", describe_result)
-
-        aws_client.cloudformation.delete_stack(StackName=stack_name)
+        with pytest.raises(ClientError) as e:
+            aws_client.cloudformation.create_stack(StackName=stack_name, TemplateBody=template_url)
+        snapshot.match("stack_create_ec2", e.value)
 
     @markers.aws.validated
     @pytest.mark.parametrize("fileformat", ["yaml", "json"])
diff --git a/tests/aws/services/cloudformation/api/test_stacks.snapshot.json b/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
index 689e7bb61bf0c..8bf66e2269025 100644
--- a/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
+++ b/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
@@ -4348,39 +4348,10 @@
       }
     }
   },
-  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_create_stack_from_template": {
-    "recorded-date": "22-10-2025, 22:04:58",
+  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_create_stack_url_as_template": {
+    "recorded-date": "23-10-2025, 18:51:49",
     "recorded-content": {
-      "stack_create_ec2": {
-        "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:1>",
-        "ResponseMetadata": {
-          "HTTPHeaders": {},
-          "HTTPStatusCode": 200
-        }
-      },
-      "stack_description": {
-        "Stacks": [
-          {
-            "CreationTime": "datetime",
-            "DisableRollback": false,
-            "DriftInformation": {
-              "StackDriftStatus": "NOT_CHECKED"
-            },
-            "EnableTerminationProtection": false,
-            "LastUpdatedTime": "datetime",
-            "NotificationARNs": [],
-            "RollbackConfiguration": {},
-            "StackId": "arn:<partition>:cloudformation:<region>:111111111111:stack/<stack-name:1>/<resource:1>",
-            "StackName": "<stack-name:1>",
-            "StackStatus": "CREATE_COMPLETE",
-            "Tags": []
-          }
-        ],
-        "ResponseMetadata": {
-          "HTTPHeaders": {},
-          "HTTPStatusCode": 200
-        }
-      }
+      "stack_create_ec2": "An error occurred (ValidationError) when calling the CreateStack operation: Template format error: unsupported structure."
     }
   }
 }

From 400858ee58f39c6db790d9f06eb1e8404241cfdf Mon Sep 17 00:00:00 2001
From: Mateusz Kiersnowski <mateusz.kiersnowski@gmail.com>
Date: Thu, 23 Oct 2025 21:17:57 +0200
Subject: [PATCH 4/5] remove unused template

---
 tests/aws/templates/ec2_cfn_init_template.yml | 67 -------------------
 1 file changed, 67 deletions(-)
 delete mode 100644 tests/aws/templates/ec2_cfn_init_template.yml

diff --git a/tests/aws/templates/ec2_cfn_init_template.yml b/tests/aws/templates/ec2_cfn_init_template.yml
deleted file mode 100644
index dce052b4ec7e7..0000000000000
--- a/tests/aws/templates/ec2_cfn_init_template.yml
+++ /dev/null
@@ -1,67 +0,0 @@
-AWSTemplateFormatVersion: "2010-09-09"
-
-Description: "AWS CloudFormation sample template.  \nCreate an Amazon EC2 instance with cfn-init and cfn-signal.\n"
-
-Resources:
-  Instance:
-    CreationPolicy:
-      ResourceSignal:
-        Timeout: PT5M
-    Type: AWS::EC2::Instance
-    Metadata:
-      guard:
-        SuppressedRules:
-          - EC2_INSTANCES_IN_VPC
-      AWS::CloudFormation::Init:
-        config:
-          packages:
-            yum:
-              httpd: []
-          files:
-            /var/www/html/index.html:
-              content: |
-                <body>
-                  <h1>Congratulations, you have successfully launched the AWS CloudFormation sample.</h1>
-                </body>
-              mode: "000644"
-              owner: root
-              group: root
-            /etc/cfn/cfn-hup.conf:
-              content: !Sub |
-                [main]
-                stack=${AWS::StackId}
-                region=${AWS::Region}
-              mode: "000400"
-              owner: root
-              group: root
-            /etc/cfn/hooks.d/cfn-auto-reloader.conf:
-              content: !Sub |-
-                [cfn-auto-reloader-hook]
-                triggers=post.update
-                path=Resources.LaunchConfig.Metadata.AWS::CloudFormation::Init
-                action=/opt/aws/bin/cfn-init -v --stack ${AWS::StackName} --resource Instance --region ${AWS::Region}
-                runas=root
-          services:
-            sysvinit:
-              httpd:
-                enabled: true
-                ensureRunning: true
-              cfn-hup:
-                enabled: true
-                ensureRunning: true
-                files:
-                  - /etc/cfn/cfn-hup.conf
-                  - /etc/cfn/hooks.d/cfn-auto-reloader.conf
-    Properties:
-      ImageId: '{{resolve:ssm:/aws/service/ami-amazon-linux-latest/al2023-ami-kernel-6.1-arm64}}'
-      InstanceType: t4g.nano
-      KeyName: sample
-      BlockDeviceMappings:
-        - DeviceName: /dev/sda1
-          Ebs:
-            VolumeSize: 32
-      UserData: !Base64
-        Fn::Sub: |-
-          #!/bin/bash
-          /opt/aws/bin/cfn-init -v --stack ${AWS::StackName} --resource Instance --region ${AWS::Region}
-          /opt/aws/bin/cfn-signal -e $? --stack ${AWS::StackName} --resource Instance --region ${AWS::Region}

From 8b40b541e001bf6c8cc7b27fa229850c4caa9f8d Mon Sep 17 00:00:00 2001
From: Mateusz Kiersnowski <mateusz.kiersnowski@gmail.com>
Date: Thu, 23 Oct 2025 21:26:40 +0200
Subject: [PATCH 5/5] validate against AWS

---
 tests/aws/services/cloudformation/api/test_stacks.py     | 2 +-
 .../cloudformation/api/test_stacks.snapshot.json         | 2 +-
 .../cloudformation/api/test_stacks.validation.json       | 9 +++++++++
 3 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/tests/aws/services/cloudformation/api/test_stacks.py b/tests/aws/services/cloudformation/api/test_stacks.py
index 0189a32a9f607..8939ecb816fb2 100644
--- a/tests/aws/services/cloudformation/api/test_stacks.py
+++ b/tests/aws/services/cloudformation/api/test_stacks.py
@@ -183,7 +183,7 @@ def test_stack_name_creation(self, deploy_cfn_template, snapshot, aws_client):
 
             snapshot.match("stack_response", e.value.response)
 
-    @markers.aws.unknown
+    @markers.aws.validated
     def test_create_stack_url_as_template(self, snapshot, aws_client):
         snapshot.add_transformer(snapshot.transform.cloudformation_api())
 
diff --git a/tests/aws/services/cloudformation/api/test_stacks.snapshot.json b/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
index 8bf66e2269025..0a6415fd994ee 100644
--- a/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
+++ b/tests/aws/services/cloudformation/api/test_stacks.snapshot.json
@@ -4349,7 +4349,7 @@
     }
   },
   "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_create_stack_url_as_template": {
-    "recorded-date": "23-10-2025, 18:51:49",
+    "recorded-date": "23-10-2025, 19:25:10",
     "recorded-content": {
       "stack_create_ec2": "An error occurred (ValidationError) when calling the CreateStack operation: Template format error: unsupported structure."
     }
diff --git a/tests/aws/services/cloudformation/api/test_stacks.validation.json b/tests/aws/services/cloudformation/api/test_stacks.validation.json
index 9dd42d7bd0ce4..adab0cbddb4a3 100644
--- a/tests/aws/services/cloudformation/api/test_stacks.validation.json
+++ b/tests/aws/services/cloudformation/api/test_stacks.validation.json
@@ -1,4 +1,13 @@
 {
+  "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_create_stack_url_as_template": {
+    "last_validated_date": "2025-10-23T19:25:10+00:00",
+    "durations_in_seconds": {
+      "setup": 0.82,
+      "call": 0.82,
+      "teardown": 0.02,
+      "total": 1.66
+    }
+  },
   "tests/aws/services/cloudformation/api/test_stacks.py::TestStacksApi::test_failure_options_for_stack_update[False-2]": {
     "last_validated_date": "2024-06-25T17:21:51+00:00"
   },