Summary
vLLM loads Hugging Face auto_map dynamic modules during model resolution without gating on trust_remote_code, allowing attacker-controlled Python code in a model repo/path to execute at server startup.
Impact
An attacker who can influence the model repo/path (local directory or remote Hugging Face repo) can achieve arbitrary code execution on the vLLM host during model load.
This happens before any request handling and does not require API access.
Affected Versions
All versions where vllm/model_executor/models/registry.py resolves auto_map entries with try_get_class_from_dynamic_module without checking trust_remote_code (at least current main).
Details
During model resolution, vLLM unconditionally iterates auto_map entries from the model config and calls try_get_class_from_dynamic_module, which delegates to Transformers’ get_class_from_dynamic_module and executes the module code.
This occurs even when trust_remote_code is false, allowing a malicious model repo to embed code in a referenced module and have it executed during initialization.
Relevant code
vllm/model_executor/models/registry.py:856 — auto_map resolution
vllm/transformers_utils/dynamic_module.py:13 — delegates to get_class_from_dynamic_module, which executes code
Fixes
Credits
Reported by bugbunny.ai
References
Summary
vLLM loads Hugging Face
auto_mapdynamic modules during model resolution without gating ontrust_remote_code, allowing attacker-controlled Python code in a model repo/path to execute at server startup.Impact
An attacker who can influence the model repo/path (local directory or remote Hugging Face repo) can achieve arbitrary code execution on the vLLM host during model load.
This happens before any request handling and does not require API access.
Affected Versions
All versions where
vllm/model_executor/models/registry.pyresolvesauto_mapentries withtry_get_class_from_dynamic_modulewithout checkingtrust_remote_code(at least currentmain).Details
During model resolution, vLLM unconditionally iterates
auto_mapentries from the model config and callstry_get_class_from_dynamic_module, which delegates to Transformers’get_class_from_dynamic_moduleand executes the module code.This occurs even when
trust_remote_codeisfalse, allowing a malicious model repo to embed code in a referenced module and have it executed during initialization.Relevant code
vllm/model_executor/models/registry.py:856— auto_map resolutionvllm/transformers_utils/dynamic_module.py:13— delegates toget_class_from_dynamic_module, which executes codeFixes
Credits
Reported by bugbunny.ai
References