huggingface transformers up to 5.4.x Python AutoModel.from_pretrained trust_remote_code inclusion of functionality from untrusted control sphere

Summaryinfo

A vulnerability labeled as problematic has been found in huggingface transformers up to 5.4.x. Affected by this vulnerability is the function AutoModel.from_pretrained of the component Python Module. Such manipulation of the argument trust_remote_code leads to inclusion of functionality from untrusted control sphere. This vulnerability is documented as CVE-2026-5241. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in huggingface transformers up to 5.4.x. It has been rated as problematic. Affected by this issue is the function AutoModel.from_pretrained of the component Python Module. The manipulation of the argument trust_remote_code with an unknown input leads to a inclusion of functionality from untrusted control sphere vulnerability. Using CWE to declare the problem leads to CWE-829. The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere. Impacted is confidentiality, integrity, and availability. CVE summarizes:

A vulnerability in the LightGlue model loading path of huggingface/transformers version 5.2.0 allows an attacker-controlled model repository to execute arbitrary code during model initialization. The issue arises because the `trust_remote_code` parameter, intended to prevent remote code execution, is overridden by untrusted serialized configuration data in a nested code path. Specifically, when loading a LightGlue model using `AutoModel.from_pretrained()` with `trust_remote_code=False`, the `LightGlueConfig` reads the `trust_remote_code` value from the untrusted `config.json` file and propagates it into nested `AutoConfig.from_pretrained()` calls. This results in the execution of attacker-provided Python modules, even when the victim explicitly disables remote code execution. The vulnerability poses a high risk for environments such as API inference servers, research notebooks, CI/CD pipelines, and model evaluation workers, potentially leading to credential theft, lateral movement, or persistence/backdoor deployment.

The advisory is available at huntr.com. This vulnerability is handled as CVE-2026-5241 since 03/31/2026. The exploitation is known to be difficult. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit.

Upgrading to version 5.5.0 eliminates this vulnerability. Applying the patch 676559d5022b74aaa0cee1cee0842b7f27c5320e is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Vendor

• huggingface

Name

• transformers

Version

• 5.0
• 5.1
• 5.2
• 5.3
• 5.4

License

• open-source

Website

• Product: https://github.com/huggingface/transformers/

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