datamodel-code-generator generates Python data models from schema definitions. Prior to 0.60.1, GraphQL Union description values in src/datamodel_code_generator/model/template/UnionTypeStatement.jinja2 and src/datamodel_code_generator/model/template/UnionTypeStatement.py312.jinja2 are rendered into Python comments without neutralizing carriage returns in Python # comments, allowing attacker-controlled GraphQL schema content to inject Python code into generated models that runs when imported. This issue is fixed in version 0.60.1.

Affected: PyPI: datamodel-code-generator

### Summary

`datamodel-code-generator` is vulnerable to code injection when generating Python models from an attacker-controlled GraphQL schema. A description on a Union type, written in the regular-string form (`"..."`) with a literal `\r` escape, is rendered into a Python `#` comment by a Jinja2 filter that handles only `\n`. Python's tokenizer treats a bare CR as a physical-line terminator, so the comment ends at the `\r` and the text after it is parsed as module-level Python. The injected code executes at `import` time of the generated `.py`, in the context of any consumer that imports the model. No special CLI flags are required.

This affects versions `>=0.25.0, <0.60.1` and is fixed in `0.60.1`.

### Details

The vulnerable output was generated by the GraphQL Union templates:

- `src/datamodel_code_generator/model/template/UnionTypeStatement.jinja2` - `src/datamodel_code_generator/model/template/UnionTypeAliasAnnotation.jinja2` - `src/datamodel_code_generator/model/template/UnionTypeAliasType.jinja2`

Before `0.60.1`, Union descriptions were rendered as Python comments using logic equivalent to `# {{ description | replace('\n', '\n# ') }}`.

The Jinja2 `replace` filter handled `\n`, but bare `\r` was not normalized. Python's lexical analysis treats CR, LF, and CRLF as physical line terminators. As a result, a malicious GraphQL schema could cause the generated Python comment to end early and emit attacker-controlled text as module-level Python code.

The `description`…

Affected: PyPI: datamodel-code-generator

### Summary

`datamodel-code-generator` is vulnerable to code injection when generating Python models from an attacker-controlled GraphQL schema. A description on a Union type, written in the regular-string form (`"..."`) with a literal `\r` escape, is rendered into a Python `#` comment by a Jinja2 filter that handles only `\n`. Python's tokenizer treats a bare CR as a physical-line terminator, so the comment ends at the `\r` and the text after it is parsed as module-level Python. The injected code executes at `import` time of the generated `.py`, in the context of any consumer that imports the model. No special CLI flags are required.

This affects versions `>=0.25.0, <0.60.1` and is fixed in `0.60.1`.

### Details

The vulnerable output was generated by the GraphQL Union templates:

- `src/datamodel_code_generator/model/template/UnionTypeStatement.jinja2` - `src/datamodel_code_generator/model/template/UnionTypeAliasAnnotation.jinja2` - `src/datamodel_code_generator/model/template/UnionTypeAliasType.jinja2`

Before `0.60.1`, Union descriptions were rendered as Python comments using logic equivalent to `# {{ description | replace('\n', '\n# ') }}`.

The Jinja2 `replace` filter handled `\n`, but bare `\r` was not normalized. Python's lexical analysis treats CR, LF, and CRLF as physical line terminators. As a result, a malicious GraphQL schema could cause the generated Python comment to end early and emit attacker-controlled text as module-level Python code.

The `description`…