---
id: CVE-2025-3262
aliases:
  - GHSA-489j-g2vx-39wf
  - PYSEC-2026-1979
title: Transformers vulnerable to ReDoS attack through its SETTING_RE variable
summary: Transformers vulnerable to ReDoS attack through its SETTING_RE variable
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'
vendor: transformers
product: transformers
ecosystem: pip
affected:
  - 'transformers >= 4.49.0, < 4.51.0'
patched:
  - transformers 4.51.0
published: '2025-07-07'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-489j-g2vx-39wf'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-3262'
  - url: >-
      https://github.com/huggingface/transformers/commit/0720e206c6ba28887e4d60ef60a6a089f6c1cc76
  - url: >-
      https://github.com/huggingface/transformers/commit/126abe3461762e5fc180e7e614391d1b4ab051ca
  - url: 'https://github.com/huggingface/transformers'
  - url: 'https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184'
tags:
  - osv
  - pip
epss: 0.00434
epssPercentile: 0.37169
ingestedAt: '2026-07-08T18:25:45.289Z'
---

## Overview

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 packages

- `transformers >= 4.49.0, < 4.51.0`

## Remediation

Upgrade to a patched release:

- `transformers 4.51.0`