CVE-2026-1839

Description

A vulnerability in the HuggingFace Transformers library, specifically in the `Trainer` class, allows for arbitrary code execution. The `_load_rng_state()` method in `src/transformers/trainer.py` at line 3059 calls `torch.load()` without the `weights_only=True` parameter. This issue affects all versions of the library supporting `torch>=2.2` when used with PyTorch versions below 2.6, as the `safe_globals()` context manager provides no protection in these versions. An attacker can exploit this vulnerability by supplying a malicious checkpoint file, such as `rng_state.pth`, which can execute arbitrary code when loaded. The issue is resolved in version v5.0.0rc3.

Weakness classification

• CWE-502: Deserialization of Untrusted Data

Primary references

• security@huntr.dev — Patch
• security@huntr.dev — Exploit, Third Party Advisory
• 134c704f-9b21-4f2e-91b3-4a467353bcc0 — Exploit, Third Party Advisory