CVE-2026-80047: Hugging Face Transformers library writes remote code to disk prior to consent check

Vulnerability summary

CVE-2026-80047 is a high (CVSS 7.8) Improper Check for Dropped Privileges vulnerability in hugging face transformers. EPSS estimates a 0.10% chance of exploitation in the next 30 days, higher than 0.7% of scored vulnerabilities.

Timeline

1. 01-09-2026
   PublishedVulnerability first disclosed.
2. 23-09-2026
   Last modifiedVulnerability information updated.

Description

A vulnerability in Hugging Face Transformers (versions 4.57.0 to 5.16.1) allows remote Python files to be written to local disk without user consent when using GenerativePreTrainedModel.load_custom_generate(). The function fetches and caches a remote module file before performing the required trust_remote_code consent check, inverting the security model enforced by other code-loading paths (such as AutoConfig, AutoModel, and AutoTokenizer). As a result, attacker‑controlled Python code from custom_generate/generate.py is copied into the user’s ~/.cache/huggingface/modules directory even if the user declines the trust prompt. Although execution is correctly gated, the file write is not reversible and can persist across sessions. This can lead to persistent, unauthorized files on disk and stale cache collisions where cached attacker code may later be executed during trusted model loads. The issue stems from an unconditional file write in dynamic_module_utils.py prior to any trust verification.

• CWE-273Improper Check for Dropped PrivilegesThe product attempts to drop privileges but does not check or incorrectly checks to see if the drop succeeded.
• CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionThe product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
• CWE-494Download of Code Without Integrity CheckThe product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.