diff --git a/doc/changes/unreleased.md b/doc/changes/unreleased.md
index 4dfeba0af..29f939fba 100644
--- a/doc/changes/unreleased.md
+++ b/doc/changes/unreleased.md
@@ -10,3 +10,4 @@
 
 * #664: Removed deprecation warning for projects to switch over to BaseConfig
 * #637: Added id to workflow templates  & synchronized on naming conventions
+* #702: Fixed StepCustomization.content to list[StepContent] and security concern for `update_cookiecutter_default`
diff --git a/exasol/toolbox/util/release/cookiecutter.py b/exasol/toolbox/util/release/cookiecutter.py
index 82b2a89bb..67b70d6af 100644
--- a/exasol/toolbox/util/release/cookiecutter.py
+++ b/exasol/toolbox/util/release/cookiecutter.py
@@ -6,12 +6,15 @@
 
 from exasol.toolbox.util.version import Version
 
+PROJECT_ROOT = Path(__file__).resolve().parents[4]
+COOKIECUTTER_JSON = PROJECT_ROOT / "project-template" / "cookiecutter.json"
 
-def update_cookiecutter_default(cookiecutter_json: Path, version: Version) -> None:
-    contents = cookiecutter_json.read_text()
+
+def update_cookiecutter_default(version: Version) -> None:
+    contents = COOKIECUTTER_JSON.read_text()
     contents_as_dict = loads(contents)
 
     contents_as_dict["exasol_toolbox_version_range"] = f">={version},<{version.major+1}"
 
     updated_contents = dumps(contents_as_dict, indent=2)
-    cookiecutter_json.write_text(updated_contents)
+    COOKIECUTTER_JSON.write_text(updated_contents)
diff --git a/exasol/toolbox/util/workflows/patch_workflow.py b/exasol/toolbox/util/workflows/patch_workflow.py
index c4bc10d5a..9b48fac6e 100644
--- a/exasol/toolbox/util/workflows/patch_workflow.py
+++ b/exasol/toolbox/util/workflows/patch_workflow.py
@@ -18,6 +18,20 @@ class ActionType(str, Enum):
 
 
 class StepContent(BaseModel):
+    """
+    The :class:`StepContent` is used to lightly validate the content which
+    would be used to REPLACE or INSERT_AFTER the specified step in the GitHub workflow.
+
+    With the value `ConfigDict(extra="allow")`, this model allows for further fields
+    (e.g. `dummy`) to be specified without any validation. This design choice was
+    intentional, as GitHub already allows additional fields and may specify more fields
+    than what has been specified in this model.
+
+    As the validation here is light, it is left to GitHub to validate the content.
+    For further information on what is allowed & expected for the fields, refer to
+    `GitHub's documentation on jobs.<job_id>.steps <https://docs.github.com/en/actions/reference/workflows-and-actions/workflow-syntax#jobsjob_idsteps>`__.
+    """
+
     model_config = ConfigDict(extra="allow")  # This allows extra fields
 
     name: str
@@ -29,19 +43,42 @@ class StepContent(BaseModel):
 
 
 class StepCustomization(BaseModel):
+    """
+    The :class:`StepCustomization` is used to specify the desired modification:
+      * REPLACE - means that the contents of the specified `step_id` should be replaced
+        with whatever `content` is provided.
+      * INSERT_AFTER - means that the specified `content` should be inserted after
+        the specified `step_id`.
+    For a given step
+    """
+
     action: ActionType
     job: str
     step_id: str
-    content: StepContent
+    content: list[StepContent]
 
 
 class Workflow(BaseModel):
+    """
+    The :class:`Workflow` is used to specify which workflow should be modified.
+    This is determined by the workflow `name`. A workflow can be modified by specifying:
+       * `remove_jobs` - job names in this list will be removed from the workflow.
+       * `step_customization` - items in this list indicate which job's step
+          should be modified.
+    """
+
     name: str
     remove_jobs: list[str] = Field(default_factory=list)
     step_customizations: list[StepCustomization] = Field(default_factory=list)
 
 
 class WorkflowPatcherConfig(BaseModel):
+    """
+    The :class:`WorkflowPatcherConfig` is used to validate the expected format for
+    the `.workflow-patcher.yml`, which is used to modify the workflow templates provided
+    by the PTB.
+    """
+
     workflows: list[Workflow]
 
 
diff --git a/noxconfig.py b/noxconfig.py
index 8f20383e3..74e1ce021 100644
--- a/noxconfig.py
+++ b/noxconfig.py
@@ -9,7 +9,10 @@
 from exasol.toolbox.config import BaseConfig
 from exasol.toolbox.nox.plugin import hookimpl
 from exasol.toolbox.tools.replace_version import update_github_yml
-from exasol.toolbox.util.release.cookiecutter import update_cookiecutter_default
+from exasol.toolbox.util.release.cookiecutter import (
+    COOKIECUTTER_JSON,
+    update_cookiecutter_default,
+)
 from exasol.toolbox.util.version import Version
 
 
@@ -33,10 +36,6 @@ def github_actions(self) -> list[Path]:
         gh_actions = self.PARENT_PATH / ".github" / "actions"
         return [f for f in gh_actions.rglob("*") if f.is_file()]
 
-    @property
-    def cookiecutter_json(self) -> Path:
-        return self.PARENT_PATH / "project-template" / "cookiecutter.json"
-
     @hookimpl
     def prepare_release_update_version(self, session, config, version: Version) -> None:
         for workflow in self.github_template_workflows:
@@ -45,14 +44,12 @@ def prepare_release_update_version(self, session, config, version: Version) -> N
         for action in self.github_actions:
             update_github_yml(action, version)
 
-        update_cookiecutter_default(self.cookiecutter_json, version)
+        update_cookiecutter_default(version)
 
     @hookimpl
     def prepare_release_add_files(self, session, config) -> list[Path]:
         return (
-            self.github_template_workflows
-            + self.github_actions
-            + [self.cookiecutter_json]
+            self.github_template_workflows + self.github_actions + [COOKIECUTTER_JSON]
         )
 
 
diff --git a/test/unit/util/release/cookiecutter_test.py b/test/unit/util/release/cookiecutter_test.py
index e363d20a6..ed6dee49a 100644
--- a/test/unit/util/release/cookiecutter_test.py
+++ b/test/unit/util/release/cookiecutter_test.py
@@ -1,6 +1,7 @@
 from inspect import cleandoc
 from json import loads
 from pathlib import Path
+from unittest.mock import patch
 
 import pytest
 
@@ -46,7 +47,10 @@ def cookiecutter_json(tmp_path: Path) -> Path:
 def test_update_cookiecutter_default(
     cookiecutter_json, version: Version, expected: str
 ):
-    update_cookiecutter_default(cookiecutter_json=cookiecutter_json, version=version)
+    with patch(
+        "exasol.toolbox.util.release.cookiecutter.COOKIECUTTER_JSON", cookiecutter_json
+    ):
+        update_cookiecutter_default(version=version)
 
     updated_json = cookiecutter_json.read_text()
     updated_dict = loads(updated_json)
diff --git a/test/unit/util/workflows/patch_workflow_test.py b/test/unit/util/workflows/patch_workflow_test.py
index aab1acd76..dc6d98151 100644
--- a/test/unit/util/workflows/patch_workflow_test.py
+++ b/test/unit/util/workflows/patch_workflow_test.py
@@ -28,11 +28,11 @@ class ExampleYaml:
               job: Tests
               step_id: checkout-repo
               content:
-                name: SCM Checkout
-                id: checkout-repo
-                uses: actions/checkout@v6
-                with:
-                  fetch-depth: 0
+                - name: SCM Checkout
+                  id: checkout-repo
+                  uses: actions/checkout@v6
+                  with:
+                    fetch-depth: 0
         """