CVE-2026-127208

Description

datamodel-code-generator before 0.84.0 contains a code injection vulnerability that allows attackers to achieve arbitrary code execution by supplying a malicious JSON Schema with a crafted x-python-type annotation containing a string ast.Constant node in a subscript slice position, which bypasses validation in parse_python_type_annotation and _python_type_expr_from_ast. Attackers can embed malicious Python expressions such as __import__ calls within quoted string literals in the generated source code, which Pydantic v2 evaluates as a ForwardRef via eval() during model_rebuild(), resulting in arbitrary code execution on developer workstations, CI/CD pipelines, or applications that generate and import the produced models at runtime.

References

• https://github.com/datamodel-code-generator/datamodel-code-generator/commit/ebfc11d0644d37a71374b28aac06d98748e584ec
• https://github.com/datamodel-code-generator/datamodel-code-generator/releases/tag/0.84.0
• https://www.vulncheck.com/advisories/datamodel-code-generator-code-injection-via-x-python-type-annotation