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. From 0.11.6 until 0.64.0, datamodel-code-generator allows attacker-controlled x-python-import or customTypePath schema extensions to reach src/datamodel_code_generator/parser/jsonschema.py and generated import handling through Import.from_full_path and Imports.create_line in src/datamodel_code_generator/imports.py, allowing a newline to break out of an import statement and execute Python code when the generated model is imported. This issue is fixed in version 0.64.0.

Affected: PyPI: datamodel-code-generator

#### Summary

A malicious input schema (OpenAPI / JSON Schema) can execute arbitrary Python code on the machine that **imports** the generated model. The `x-python-import` and `customTypePath` schema extensions flow, unsanitized, into the `import` statements datamodel-code-generator emits. A newline embedded in the extension value breaks out of the `from … import …` line and injects an attacker-controlled statement at module scope, which runs at import time. This is an unauthenticated, schema-content–driven remote code execution against any consumer of the generated code (e.g. arbitrary file read,the PoC exfiltrates `/etc/passwd`). It survives the v0.61.0 security release that fixed the related `x-python-type`, `default_factory`, GraphQL-union-description, and `validators` sinks those fixes did not cover this sibling path.

#### Details

The sink is `Import.from_full_path` and `Imports.create_line`:

- `src/datamodel_code_generator/imports.py:35` — `from_full_path()` only does `class_path.split(".")` and preserves every other character, **including newlines**: ```python @classmethod @lru_cache def from_full_path(cls, class_path: str) -> Import: split_class_path: list[str] = class_path.split(".") return cls(import_=split_class_path[-1], from_=".".join(split_class_path[:-1]) or None) ``` - `src/datamodel_code_generator/imports.py:64` — `create_line()` renders the result verbatim: ```python def create_line(self, from_: str | None, imports: set[str]) -…

Affected: PyPI: datamodel-code-generator

#### Summary

A malicious input schema (OpenAPI / JSON Schema) can execute arbitrary Python code on the machine that **imports** the generated model. The `x-python-import` and `customTypePath` schema extensions flow, unsanitized, into the `import` statements datamodel-code-generator emits. A newline embedded in the extension value breaks out of the `from … import …` line and injects an attacker-controlled statement at module scope, which runs at import time. This is an unauthenticated, schema-content–driven remote code execution against any consumer of the generated code (e.g. arbitrary file read,the PoC exfiltrates `/etc/passwd`). It survives the v0.61.0 security release that fixed the related `x-python-type`, `default_factory`, GraphQL-union-description, and `validators` sinks those fixes did not cover this sibling path.

#### Details

The sink is `Import.from_full_path` and `Imports.create_line`:

- `src/datamodel_code_generator/imports.py:35` — `from_full_path()` only does `class_path.split(".")` and preserves every other character, **including newlines**: ```python @classmethod @lru_cache def from_full_path(cls, class_path: str) -> Import: split_class_path: list[str] = class_path.split(".") return cls(import_=split_class_path[-1], from_=".".join(split_class_path[:-1]) or None) ``` - `src/datamodel_code_generator/imports.py:64` — `create_line()` renders the result verbatim: ```python def create_line(self, from_: str | None, imports: set[str]) -…