Regular Expression Denial of Service (ReDoS) in huggingface/transformers

{
  "id": "0e5c99ddd963a57117ba350e91515d2afc04122d17a4d4955ac7554d188caf07",
  "url": "https://osv.dev/vulnerability/CVE-2025-6051",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Regular Expression Denial of Service (ReDoS) in huggingface/transformers",
    "summary": "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.",
    "evidence": "osv:CVE-2025-6051",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2025-6051",
      "aliases": [
        "CVE-2025-6051",
        "GHSA-rcv9-qm8p-9p6j",
        "PYSEC-2026-1988"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/huggingface/transformers",
              "type": "GIT",
              "events": [
                {
                  "introduced": "51f94ea06d19a6308c61bbb4dc97c40aabd12bad"
                },
                {
                  "fixed": "ba8eaba9865618253f997784aa565b96206426f0"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:huggingface:transformers:4.52.4:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "4.52.4"
                      },
                      {
                        "last_affected": "4.52.4"
                      }
                    ],
                    "source": "CPE_STRING"
                  },
                  {
                    "range": [
                      {
                        "fixed": "ba8eaba9865618253f997784aa565b96206426f0"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "4.52.4"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-6051.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:22.622541068Z",
      "provider": "osv",
      "references": [
        "https://huntr.com/bounties/af929523-7b59-418a-bf55-301830b2ac9d",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/6xxx/CVE-2025-6051.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-6051",
        "https://github.com/huggingface/transformers/commit/ba8eaba9865618253f997784aa565b96206426f0"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1333"
        ],
        "cna_assigner": "@huntr_ai",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/6xxx/CVE-2025-6051.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-6051",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 488977,
  "published_at": "2025-09-14T17:03:02.953+00:00"
}