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PYSEC-2026-1988

Vulnerability from pysec - Published: 2026-07-07 16:03 - Updated: 2026-07-07 17:25
VLAI
Details

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically within the normalize_numbers() method of the EnglishNormalizer class. This vulnerability affects versions up to 4.52.4 and is fixed in version 4.53.0. The issue arises from the method's handling of numeric strings, which can be exploited using crafted input strings containing long sequences of digits, leading to excessive CPU consumption. This vulnerability impacts text-to-speech and number normalization tasks, potentially causing service disruption, resource exhaustion, and API vulnerabilities.

Severity
5.3 (Medium)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Impacted products
Name purl
transformers pkg:pypi/transformers
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "transformers",
        "purl": "pkg:pypi/transformers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.53.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1",
        "2.0.0",
        "2.1.0",
        "2.1.1",
        "2.10.0",
        "2.11.0",
        "2.2.0",
        "2.2.1",
        "2.2.2",
        "2.3.0",
        "2.4.0",
        "2.4.1",
        "2.5.0",
        "2.5.1",
        "2.6.0",
        "2.7.0",
        "2.8.0",
        "2.9.0",
        "2.9.1",
        "3.0.0",
        "3.0.1",
        "3.0.2",
        "3.1.0",
        "3.2.0",
        "3.3.0",
        "3.3.1",
        "3.4.0",
        "3.5.0",
        "3.5.1",
        "4.0.0",
        "4.0.0rc1",
        "4.0.1",
        "4.1.0",
        "4.1.1",
        "4.10.0",
        "4.10.1",
        "4.10.2",
        "4.10.3",
        "4.11.0",
        "4.11.1",
        "4.11.2",
        "4.11.3",
        "4.12.0",
        "4.12.1",
        "4.12.2",
        "4.12.3",
        "4.12.4",
        "4.12.5",
        "4.13.0",
        "4.14.0",
        "4.14.1",
        "4.15.0",
        "4.16.0",
        "4.16.1",
        "4.16.2",
        "4.17.0",
        "4.18.0",
        "4.19.0",
        "4.19.1",
        "4.19.2",
        "4.19.3",
        "4.19.4",
        "4.2.0",
        "4.2.1",
        "4.2.2",
        "4.20.0",
        "4.20.1",
        "4.21.0",
        "4.21.1",
        "4.21.2",
        "4.21.3",
        "4.22.0",
        "4.22.1",
        "4.22.2",
        "4.23.0",
        "4.23.1",
        "4.24.0",
        "4.25.0",
        "4.25.1",
        "4.26.0",
        "4.26.1",
        "4.27.0",
        "4.27.1",
        "4.27.2",
        "4.27.3",
        "4.27.4",
        "4.28.0",
        "4.28.1",
        "4.29.0",
        "4.29.1",
        "4.29.2",
        "4.3.0",
        "4.3.0rc1",
        "4.3.1",
        "4.3.2",
        "4.3.3",
        "4.30.0",
        "4.30.1",
        "4.30.2",
        "4.31.0",
        "4.32.0",
        "4.32.1",
        "4.33.0",
        "4.33.1",
        "4.33.2",
        "4.33.3",
        "4.34.0",
        "4.34.1",
        "4.35.0",
        "4.35.1",
        "4.35.2",
        "4.36.0",
        "4.36.1",
        "4.36.2",
        "4.37.0",
        "4.37.1",
        "4.37.2",
        "4.38.0",
        "4.38.1",
        "4.38.2",
        "4.39.0",
        "4.39.1",
        "4.39.2",
        "4.39.3",
        "4.4.0",
        "4.4.1",
        "4.4.2",
        "4.40.0",
        "4.40.1",
        "4.40.2",
        "4.41.0",
        "4.41.1",
        "4.41.2",
        "4.42.0",
        "4.42.1",
        "4.42.2",
        "4.42.3",
        "4.42.4",
        "4.43.0",
        "4.43.1",
        "4.43.2",
        "4.43.3",
        "4.43.4",
        "4.44.0",
        "4.44.1",
        "4.44.2",
        "4.45.0",
        "4.45.1",
        "4.45.2",
        "4.46.0",
        "4.46.1",
        "4.46.2",
        "4.46.3",
        "4.47.0",
        "4.47.1",
        "4.48.0",
        "4.48.1",
        "4.48.2",
        "4.48.3",
        "4.49.0",
        "4.5.0",
        "4.5.1",
        "4.50.0",
        "4.50.1",
        "4.50.2",
        "4.50.3",
        "4.51.0",
        "4.51.1",
        "4.51.2",
        "4.51.3",
        "4.52.0",
        "4.52.1",
        "4.52.2",
        "4.52.3",
        "4.52.4",
        "4.6.0",
        "4.6.1",
        "4.7.0",
        "4.8.0",
        "4.8.1",
        "4.8.2",
        "4.9.0",
        "4.9.1",
        "4.9.2"
      ]
    }
  ],
  "aliases": [
    "CVE-2025-6051",
    "GHSA-rcv9-qm8p-9p6j"
  ],
  "details": "A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically within the `normalize_numbers()` method of the `EnglishNormalizer` class. This vulnerability affects versions up to 4.52.4 and is fixed in version 4.53.0. The issue arises from the method\u0027s handling of numeric strings, which can be exploited using crafted input strings containing long sequences of digits, leading to excessive CPU consumption. This vulnerability impacts text-to-speech and number normalization tasks, potentially causing service disruption, resource exhaustion, and API vulnerabilities.",
  "id": "PYSEC-2026-1988",
  "modified": "2026-07-07T17:25:43.340070Z",
  "published": "2026-07-07T16:03:05.052410Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-6051"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/transformers/pull/38844"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/transformers/commit/54a02160eb030da9be18231c77791f2eb3a52216"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/transformers/commit/ba8eaba9865618253f997784aa565b96206426f0"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/huggingface/transformers"
    },
    {
      "type": "WEB",
      "url": "https://huntr.com/bounties/af929523-7b59-418a-bf55-301830b2ac9d"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/transformers"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-rcv9-qm8p-9p6j"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Hugging Face Transformers library has Regular Expression Denial of Service"
}



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