Description

FreeCAD is a free and open-source multiplatform 3D parametric modeler. Prior to 1.1.2, src/App/PropertyPythonObject.cpp in PropertyPythonObject::Restore() passes the attacker-controlled module attribute from serialized PropertyPythonObject XML directly to PyImport_ImportModule() while restoring a crafted FCStd document, which executes module-level Python code, and the legacy pickle branch also imports an attacker-controlled module and invokes its class constructor through PyObject_CallObject(). This issue is fixed in version 1.1.2.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.0",
  "pubDate": "2026-08-17T21:16:44.403Z",
  "pubdate": "2026-08-17T21:16:44.403Z",
  "executiveSummary": "A remote code execution vulnerability exists in FreeCAD prior to version 1.1.2.\nThe vulnerability resides in the src/App/PropertyPythonObject.cpp file within the PropertyPythonObject::Restore() function.\nThe flaw allows an attacker to execute arbitrary module-level Python code and invoke class constructors through crafted FCStd documents.\nSuccessful exploitation can lead to arbitrary code execution within the context of the running application.\nThe attack requires the victim to open a maliciously crafted document file.\nAffected systems include FreeCAD deployments running versions prior to 1.1.2.",
  "technicalDetails": "The vulnerability stems from unsafe deserialization handling in PropertyPythonObject::Restore() located within src/App/PropertyPythonObject.cpp.\nDuring the document restoration process from a crafted FCStd file, the application parses XML data and extracts an attacker-controlled module attribute.\nThis attacker-controlled attribute is passed directly to the PyImport_ImportModule() function without proper validation or sanitization.\nConsequently, the import operation triggers the execution of arbitrary module-level Python code supplied within the serialized data.\nAdditionally, the legacy pickle branch within the same restoration logic insecurely imports an attacker-controlled module and invokes its class constructor utilizing PyObject_CallObject().\nAn attacker can leverage this behavior by constructing a malicious FCStd document containing specially crafted XML or pickle payloads designed to instantiate arbitrary Python objects and execute arbitrary code.\nWhen a user opens the malicious FCStd file, FreeCAD parses the document and executes the embedded payload automatically.\nThis vulnerability affects FreeCAD versions prior to 1.1.2 and requires local interaction via opening an untrusted file to trigger the deserialization and subsequent execution flow."
}