datamodel-code-generator generates Pydantic v2 models, dataclasses, TypedDict, and msgspec.Struct from OpenAPI, JSON Schema, GraphQL, Avro, Protobuf, and raw JSON, YAML, or CSV. Prior to 0.62.0, datamodel-code-generator resolves JSON Schema $ref targets in src/datamodel_code_generator/parser/jsonschema.py through is_url and _get_ref_body without containing file:// or ../ traversal references to the input directory and without honoring --no-allow-remote-refs, allowing arbitrary local file reads. This issue is fixed in version 0.62.0.

Affected: PyPI: datamodel-code-generator

### Summary

`datamodel-code-generator` resolves JSON-Schema `$ref` targets that point at the local filesystem without restricting them to the input/base directory and without honoring the remote-reference security control. In the default configuration, an attacker who controls an input schema (a "paste your OpenAPI/JSON-Schema" service, a CI job that generates models from a submitted spec, or any multi-tenant codegen platform) can read any file the process user can read and map the host filesystem. This works via either a `file://` absolute URI or a `../`-escaped relative reference, and it succeeds even when `--no-allow-remote-refs` is set.

This is an unauthenticated path-traversal / information-disclosure issue (CWE-22 / CWE-200) plus a bypass of a documented security control.

### Details

`is_url()` classifies `file://` as a URL (`reference.py:1249`):

```python def is_url(ref: str) -> bool: return ref.startswith(("https://", "http://", "file://")) ```

The remote-ref gate then explicitly exempts `file://`, so `--no-allow-remote-refs` never applies to it (`parser/jsonschema.py`, `_get_ref_body`):

```python if is_url(resolved_ref): if not resolved_ref.startswith("file://") and self.http_local_ref_path is None: if self.allow_remote_refs is False: raise Error(...) # <-- skipped for file:// ... return self._get_ref_body_from_url(resolved_ref) return self._get_ref_body_from_remote(resolved_ref) ```

Both local-file branches rea…

Affected: PyPI: datamodel-code-generator

### Summary

`datamodel-code-generator` resolves JSON-Schema `$ref` targets that point at the local filesystem without restricting them to the input/base directory and without honoring the remote-reference security control. In the default configuration, an attacker who controls an input schema (a "paste your OpenAPI/JSON-Schema" service, a CI job that generates models from a submitted spec, or any multi-tenant codegen platform) can read any file the process user can read and map the host filesystem. This works via either a `file://` absolute URI or a `../`-escaped relative reference, and it succeeds even when `--no-allow-remote-refs` is set.

This is an unauthenticated path-traversal / information-disclosure issue (CWE-22 / CWE-200) plus a bypass of a documented security control.

### Details

`is_url()` classifies `file://` as a URL (`reference.py:1249`):

```python def is_url(ref: str) -> bool: return ref.startswith(("https://", "http://", "file://")) ```

The remote-ref gate then explicitly exempts `file://`, so `--no-allow-remote-refs` never applies to it (`parser/jsonschema.py`, `_get_ref_body`):

```python if is_url(resolved_ref): if not resolved_ref.startswith("file://") and self.http_local_ref_path is None: if self.allow_remote_refs is False: raise Error(...) # <-- skipped for file:// ... return self._get_ref_body_from_url(resolved_ref) return self._get_ref_body_from_remote(resolved_ref) ```

Both local-file branches rea…