Critical RCE Vulnerability in Hugging Face Transformers Library Disclosed

A critical remote code execution (RCE) vulnerability has been identified in the Hugging Face Transformers library, tracked as CVE-2026-4372. This flaw allows attackers to execute arbitrary code during model loading by bypassing the trust_remote_code=False safeguard. The vulnerability affects all versions from 4.56.0 to 5.2.x and was downloaded approximately 232 million times during its active period. Hugging Face released a patch for the vulnerability in version 5.3.0 on May 24, 2026. Security researchers from Pluto Security discovered the flaw, which can lead to the exposure of sensitive data such as cloud credentials and API keys. The exploit involves a parameter that appears innocuous but can execute malicious code without user consent. The vulnerability poses a significant risk to enterprise environments and automated AI pipelines.

Key Points: • CVE-2026-4372 allows RCE via Hugging Face Transformers library configurations. • The vulnerability affects versions from 4.56.0 to 5.2.x, with 232 million downloads during its active phase. • A patch was released on May 24, 2026, but many vulnerable versions remain in use.