CVE-2025-68480

Marshmallow is a lightweight library for converting complex objects to and from simple Python datatypes. In versions from 3.0.0rc1 to before 3.26.2 and from 4.0.0 to before 4.1.2, Schema.load(data, many=True) is vulnerable to denial of service attacks. A moderately sized request can consume a disproportionate amount of CPU time. This issue has been patched in version 3.26.2 and 4.1.2.

Marshmallow is a lightweight library for converting complex objects to and from simple Python datatypes. In versions from 3.0.0rc1 to before 3.26.2 and from 4.0.0 to before 4.1.2, Schema.load(data, many=True) is vulnerable to denial of service attacks. A moderately sized request can consume a disproportionate amount of CPU time. This issue has been patched in version 3.26.2 and 4.1.2.

### Impact `Schema.load(data, many=True)` is vulnerable to denial of service attacks. A moderately sized request can consume a disproportionate amount of CPU time. ### Patches 4.1.2, 3.26.2 ### Workarounds ```py # Fail fast def load_many(schema, data, **kwargs): if not isinstance(data, list): raise ValidationError(['Invalid input type.']) return [schema.load(item, **kwargs) for item in data] ```

### Impact `Schema.load(data, many=True)` is vulnerable to denial of service attacks. A moderately sized request can consume a disproportionate amount of CPU time. ### Patches 4.1.2, 3.26.2 ### Workarounds ```py # Fail fast def load_many(schema, data, **kwargs): if not isinstance(data, list): raise ValidationError(['Invalid input type.']) return [schema.load(item, **kwargs) for item in data] ```