CVE-2025-2099 Information

Description

A vulnerability in the preprocess_string() function of the transformers.testing_utils module in huggingface/transformers version v4.48.3 allows for a Regular Expression Denial of Service (ReDoS) attack. The regular expression used to process code blocks in docstrings contains nested quantifiers leading to exponential backtracking when processing input with a large number of newline characters. An attacker can exploit this by providing a specially crafted payload causing high CPU usage and potential application downtime effectively resulting in a Denial of Service (DoS) scenario.

Reference

https://github.com/huggingface/transformers/commit/8cb522b4190bd556ce51be04942720650b1a3e57 https://huntr.com/bounties/97b780f3-ffca-424f-ad5d-0e1c57a5bde4