PYSEC-2026-1983
Hugging Face Transformers Regular Expression Denial of Service (ReDoS) vulnerability
Quick fix
PYSEC-2026-1983 — transformers: upgrade to the fixed version with the command below.
pip install --upgrade 'transformers>=4.53.0'Details
A Regular Expression Denial of Service (ReDoS) vulnerability exists in the Hugging Face Transformers library, specifically in the `convert_tf_weight_name_to_pt_weight_name()` function. This function, responsible for converting TensorFlow weight names to PyTorch format, uses a regex pattern `/[^/]*___([^/]*)/` that can be exploited to cause excessive CPU consumption through crafted input strings due to catastrophic backtracking. The vulnerability affects versions up to 4.51.3 and is fixed in version 4.53.0. This issue can lead to service disruption, resource exhaustion, and potential API service vulnerabilities, impacting model conversion processes between TensorFlow and PyTorch formats.
Are you affected?
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Affected packages
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-5197[ADVISORY]
- https://github.com/huggingface/transformers/commit/701caef704e356dc2f9331cc3fd5df0eccb4720a[WEB]
- https://github.com/huggingface/transformers/commit/944b56000be5e9b61af8301aa340838770ad8a0b[WEB]
- https://github.com/huggingface/transformers[PACKAGE]
- https://huntr.com/bounties/3f8b3fd0-166b-46e7-b60f-60dd9d2678bf[WEB]
- https://pypi.org/project/transformers[PACKAGE]
- https://github.com/advisories/GHSA-9356-575x-2w9m[ADVISORY]