CVE-2025-1194: Regular Expression Denial of Service (ReDoS) in huggingface/transformers

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2025-04-29 · updated 2026-06-17
Weakness: CWE-1333

Description

A Regular Expression Denial of Service (ReDoS) vulnerability was identified in the huggingface/transformers library, specifically in the file `tokenization_gpt_neox_japanese.py` of the GPT-NeoX-Japanese model. The vulnerability occurs in the SubWordJapaneseTokenizer class, where regular expressions process specially crafted inputs. The issue stems from a regex exhibiting exponential complexity under certain conditions, leading to excessive backtracking. This can result in high CPU usage and potential application downtime, effectively creating a Denial of Service (DoS) scenario. The affected version is v4.48.1 (latest).

Affected products

huggingface/transformers: before 4.50.0 — fixed in 4.50.0

How to fix

Upgrade to a fixed version: huggingface/transformers 4.50.0. Check the vendor advisory for mitigations.

References

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