Restricted targets

Some callables are too generic or powerful for target-name authorization. Even an exact execution-whitelist entry cannot authorize these targets because the configured name does not bound the behavior that configuration can select.

Hydra's error identifies the exact rejected target and explains why it cannot be authorized.

Dynamic selection and dispatch

Attribute operations such as builtins.getattr, hasattr, setattr, and delattr let configuration select an attribute or descriptor operation as data. Generic operator helpers such as call, attrgetter, methodcaller, getitem, itemgetter, setitem, delitem, and contains have the same problem.

Name the intended callable directly as _target_, or perform the dynamic selection in trusted Python code.

Callback dispatch and callable wrappers

Dispatchers such as builtins.map, functools.reduce, itertools.starmap, and executor or pool submission APIs invoke a config-supplied callback. Invocation may continue outside Hydra's immediate callable-result checks.

Callable binding and wrapper helpers can similarly defer or obscure the effective callable. Examples include classmethod, staticmethod, functools.lru_cache, partialmethod, singledispatch, and update_wrapper.

Perform this dispatch or wrapping in trusted Python code. If configuration must request a broader operation, expose a narrow application-owned wrapper whose behavior is bounded by its target name.

Uncontrolled execution

Targets that execute code, import modules, load native libraries, spawn processes, or deserialize executable objects cannot be authorized. This includes families such as eval and exec, subprocess and shell execution, dynamic import loaders, ctypes library loading, and pickle-backed loaders.

These operations should remain in trusted Python code rather than composed configuration.

Reentrant instantiation

Do not configure hydra.utils.instantiate, hydra.utils.call, or Hydra's internal instantiate function as _target_. Reentrant instantiation does not safely preserve the effective policy. Call instantiate() from trusted Python code and pass or establish the intended execution whitelist there.

Explicitly disabling checks

warning

UNSAFE_DISABLE_EXECUTION_CHECKS disables both whitelist and blacklist checks. It permits every target described on this page. Use it only with trusted code in a trusted runtime environment, where every relevant configuration source is also trusted and unrestricted Python execution is intentional.

To disable checks explicitly for one direct instantiate() call:

from hydra.utils import UNSAFE_DISABLE_EXECUTION_CHECKS, instantiate

obj = instantiate(
    cfg.component,
    _execution_whitelist_=UNSAFE_DISABLE_EXECUTION_CHECKS,
)