What’s Vulnerable › Vulnerabilities

CVE-2025-3262: Regular Expression Denial of Service (ReDoS) in huggingface/transformers

• Severity: high (CVSS 7.5 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: 2025-07-07 · updated 2026-06-17
• Weakness: CWE-1333

Description

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.

Affected products

• huggingface/transformers: before 4.51.0 — fixed in 4.51.0

How to fix

Upgrade to a fixed version: huggingface/transformers 4.51.0. Check the vendor advisory for mitigations.

References

• https://github.com/huggingface/transformers/commit/0720e206c6ba28887e4d60ef60a6a089f6c1cc76
• https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184
• https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184

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