MEDIUM 5.3

GHSA-489j-g2vx-39wf

Transformers vulnerable to ReDoS attack through its SETTING_RE variable

Details

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the huggingface/transformers repository, specifically in version 4.49.0. The vulnerability is due to inefficient regular expression complexity in the `SETTING_RE` variable within the `transformers/commands/chat.py` file. The regex contains repetition groups and non-optimized quantifiers, leading to exponential backtracking when processing 'almost matching' payloads. This can degrade application performance and potentially result in a denial-of-service (DoS) when handling specially crafted input strings. The issue is fixed in version 4.51.0.

Are you affected?

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Affected packages

PyPI / transformers

Introduced in: 4.49.0 Fixed in: 4.51.0

Fix pip install --upgrade 'transformers>=4.51.0'

References

https://nvd.nist.gov/vuln/detail/CVE-2025-3262 [ADVISORY]
https://github.com/huggingface/transformers/commit/0720e206c6ba28887e4d60ef60a6a089f6c1cc76 [WEB]
https://github.com/huggingface/transformers/commit/126abe3461762e5fc180e7e614391d1b4ab051ca [WEB]
https://github.com/huggingface/transformers [PACKAGE]
https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184 [WEB]