CVE-2025-55201

@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file. This projec
 adheres to [PEP 440](https://www.python.org/dev/peps/pep-0440/) versioning schema, and
 the changelog itself conforms to [Keep A Changelog](https://keepachangelog.com/).
 
+## v9.9.1 (2025-08-18)
+
+### Security
+
+-   disallow render paths outside destination directory
+-   cast Jinja context path variables to `pathlib.PurePath`
+
 ## v9.9.0 (2025-08-01)
 
 ### Feat

@@ -179,7 +179,7 @@ annotated_tag = true
 changelog_incremental = true
 tag_format = "v$version"
 update_changelog_on_bump = true
-version = "9.9.0"
+version = "9.9.1"
 
 [tool.codespell]
 # Ref: https://github.com/codespell-project/codespell#using-a-config-file

@@ -13,7 +13,7 @@
 from filecmp import dircmp
 from functools import cached_property, partial, wraps
 from itertools import chain
-from pathlib import Path
+from pathlib import Path, PurePath
 from shutil import rmtree
 from tempfile import TemporaryDirectory
 from types import TracebackType
@@ -399,9 +399,9 @@ def _render_context(self) -> AnyByStrMutableMapping:
         """Produce render context for Jinja."""
         conf = LazyDict(
             {
-                "src_path": lambda: self.template.local_abspath,
-                "dst_path": lambda: self.dst_path,
-                "answers_file": lambda: self.answers_relpath,
+                "src_path": lambda: PurePath(self.template.local_abspath),
+                "dst_path": lambda: PurePath(self.dst_path),
+                "answers_file": lambda: PurePath(self.answers_relpath),
                 "vcs_ref": lambda: self.resolved_vcs_ref,
                 "vcs_ref_hash": lambda: self.template.commit_hash,
                 "data": lambda: self.data,
@@ -659,13 +659,18 @@ def jinja_env(self) -> YieldEnvironment:
                 "Make sure to install these extensions alongside Copier itself.\n"
                 "See the docs at https://copier.readthedocs.io/en/latest/configuring/#jinja_extensions"
             )
+
+        def to_json_fallback(value: Any) -> Any:
+            if isinstance(value, LazyDict):
+                return dict(value)
+            if isinstance(value, PurePath):
+                return str(value)
+            return value
+
         # patch the `to_json` filter to support Pydantic dataclasses
         env.filters["to_json"] = partial(
             env.filters["to_json"],
-            default=partial(
-                to_jsonable_python,
-                fallback=lambda v: dict(v) if isinstance(v, LazyDict) else v,
-            ),
+            default=partial(to_jsonable_python, fallback=to_json_fallback),
         )
 
         # Add a global function to join filesystem paths.

@@ -106,13 +106,13 @@ Attributes:
 
 | Name               | Type                                                          | Description                                                                                                                                                                                                                                                |
 | ------------------ | ------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
-| `answers_file`     | `Path`                                                        | The path for [the answers file][the-copier-answersyml-file] relative to `dst_path`.<br>See the [`answers_file`][] setting for related information.                                                                                                         |
+| `answers_file`     | `PurePath`                                                    | The path for [the answers file][the-copier-answersyml-file] relative to `dst_path`.<br>See the [`answers_file`][] setting for related information.                                                                                                         |
 | `cleanup_on_error` | `bool`                                                        | When `True`, delete `dst_path` if there's an error.<br>See the [`cleanup_on_error`][] setting for related information.                                                                                                                                     |
 | `conflict`         | `Literal["inline", "rej"]`                                    | The output format of a diff code hunk when [updating][updating-a-project] a file yields conflicts.<br>See the [`conflict`][] setting for related information.                                                                                              |
 | `context_lines`    | `PositiveInt`                                                 | Lines of context to consider when solving conflicts in updates.<br>See the [`context_lines`][] setting for related information.                                                                                                                            |
 | `data`             | `dict[str, Any]`                                              | Answers to the questionnaire, defined in the template, provided via CLI (`-d,--data`) or API (`data`).<br>See the [`data`][] setting for related information.<br>⚠️ May contain secret answers.                                                            |
 | `defaults`         | `bool`                                                        | When `True`, use default answers to questions.<br>See the [`defaults`][] setting for related information.                                                                                                                                                  |
-| `dst_path`         | `Path`                                                        | Destination path where to render the subproject.<br>⚠️ When [updating a project][updating-a-project], it may be a temporary directory, as Copier's update algorithm generates fresh copies using the old and new template versions in temporary locations. |
+| `dst_path`         | `PurePath`                                                    | Destination path where to render the subproject.<br>⚠️ When [updating a project][updating-a-project], it may be a temporary directory, as Copier's update algorithm generates fresh copies using the old and new template versions in temporary locations. |
 | `exclude`          | `Sequence[str]`                                               | Specified additional [file exclusion patterns][patterns-syntax].<br>See the [`exclude`][] setting for related information.                                                                                                                                 |
 | `os`               | <code>Literal["linux", "macos", "windows"] &vert; None</code> | The detected operating system, `None` if it could not be detected.                                                                                                                                                                                         |
 | `overwrite`        | `bool`                                                        | When `True`, overwrite files that already exist, without asking.<br>See the [`overwrite`][] setting for related information.                                                                                                                               |
@@ -123,7 +123,7 @@ Attributes:
 | `skip_answered`    | `bool`                                                        | When `True`, skip questions that have already been answered.<br>See the [`skip_answered`][] setting for related information.                                                                                                                               |
 | `skip_if_exists`   | `Sequence[str]`                                               | Specified additional [file skip patterns][patterns-syntax].<br>See the [`skip_if_exists`][] setting for related information.                                                                                                                               |
 | `skip_tasks`       | `bool`                                                        | When `True`, skip [template tasks execution][tasks].<br>See the [`skip_tasks`][] setting for related information.                                                                                                                                          |
-| `src_path`         | `Path`                                                        | The absolute path to the (cloned/downloaded) template on disk.                                                                                                                                                                                             |
+| `src_path`         | `PurePath`                                                    | The absolute path to the (cloned/downloaded) template on disk.                                                                                                                                                                                             |
 | `unsafe`           | `bool`                                                        | When `True`, allow usage of unsafe templates.<br>See the [`unsafe`][] setting for related information.                                                                                                                                                     |
 | `use_prereleases`  | `bool`                                                        | When `True`, `vcs_ref`/`vcs_ref_hash` may refer to a prerelease version of the template.<br>See the [`use_prereleases`][] setting for related information.                                                                                                 |
 | `user_defaults`    | `dict[str, Any]`                                              | Specified user defaults that may override a template's defaults during question prompts.                                                                                                                                                                   |

@@ -1,5 +1,7 @@
 import json
+import sys
 from pathlib import Path
+from uuid import uuid4
 
 import pytest
 from plumbum import local
@@ -9,6 +11,60 @@
 from .helpers import build_file_tree, git_save
 
 
+def test_no_path_variables(
+    tmp_path_factory: pytest.TempPathFactory, monkeypatch: pytest.MonkeyPatch
+) -> None:
+    """Test that there are no context variables of type `pathlib.Path`."""
+    src, dst = map(tmp_path_factory.mktemp, ("src", "dst"))
+    ext_module_name = uuid4()
+    build_file_tree(
+        {
+            src / f"{ext_module_name}.py": (
+                """\
+                from pathlib import Path
+                from typing import Any, Mapping
+
+                from jinja2 import Environment, pass_context
+                from jinja2.ext import Extension
+                from jinja2.runtime import Context
+                from pydantic import BaseModel
+
+
+                class ContextExtension(Extension):
+                    def __init__(self, environment: Environment) -> None:
+                        super().__init__(environment)
+                        environment.globals["__assert"] = self._assert
+
+                    @pass_context
+                    def _assert(self, ctx: Context) -> None:
+                        items: list[tuple[str, Any]] = list(dict(ctx).items())
+                        for k, v in items:
+                            if isinstance(v, Path):
+                                raise AssertionError(
+                                    f"{k} must not be a `pathlib.Path` object"
+                                )
+                            if isinstance(v, BaseModel):
+                                v = dict(v)
+                            if isinstance(v, Mapping):
+                                items.extend((f"{k}.{k2}", v2) for k2, v2 in v.items())
+                            elif isinstance(v, (list, tuple, set)):
+                                items.extend((f"{k}[{i}]", v2) for i, v2 in enumerate(v))
+                """
+            ),
+            src / "copier.yml": (
+                f"""\
+                _jinja_extensions:
+                    - {ext_module_name}.ContextExtension
+                """
+            ),
+            src / "test.txt.jinja": "{{ __assert() | default('', true) }}",
+        }
+    )
+    monkeypatch.setattr("sys.path", [str(src), *sys.path])
+    copier.run_copy(str(src), dst, unsafe=True)
+    assert (dst / "test.txt").read_text("utf-8") == ""
+
+
 def test_exclude_templating_with_operation(
     tmp_path_factory: pytest.TempPathFactory,
 ) -> None: