Vulnerability-Lookup

PYSEC-2026-1979

Vulnerability from pysec - Published: 2026-07-07 16:02 - Updated: 2026-07-07 17:25

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.

Severity

5.3 (Medium)


                  
                    CVSS:3.1/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

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "transformers",
        "purl": "pkg:pypi/transformers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.49.0"
            },
            {
              "fixed": "4.51.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.49.0",
        "4.50.0",
        "4.50.1",
        "4.50.2",
        "4.50.3"
      ]
    }
  ],
  "aliases": [
    "CVE-2025-3262",
    "GHSA-489j-g2vx-39wf"
  ],
  "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 \u0027almost matching\u0027 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.",
  "id": "PYSEC-2026-1979",
  "modified": "2026-07-07T17:25:42.734398Z",
  "published": "2026-07-07T16:02:56.726858Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-3262"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/transformers/commit/0720e206c6ba28887e4d60ef60a6a089f6c1cc76"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/transformers/commit/126abe3461762e5fc180e7e614391d1b4ab051ca"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/huggingface/transformers"
    },
    {
      "type": "WEB",
      "url": "https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/transformers"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-489j-g2vx-39wf"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Transformers vulnerable to ReDoS attack through its SETTING_RE variable"
}

CVE-2025-3262 (GCVE-0-2025-3262)

Vulnerability from cvelistv5 – Published: 2025-07-07 09:54 – Updated: 2025-07-07 15:19

Title

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

Summary

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.

Severity

5.3 (Medium)


                        
                          CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-1333 - Inefficient Regular Expression Complexity

Assigner

@huntr_ai

References

2 references

URL	Tags
https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b54…
https://github.com/huggingface/transformers/commi…

Impacted products

1 product

Vendor	Product	Version
huggingface	huggingface/transformers	Affected: unspecified , < 4.51.0 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-3262",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-07-07T15:19:35.031775Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-07-07T15:19:42.413Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "huggingface/transformers",
          "vendor": "huggingface",
          "versions": [
            {
              "lessThan": "4.51.0",
              "status": "affected",
              "version": "unspecified",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "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 \u0027almost matching\u0027 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."
        }
      ],
      "metrics": [
        {
          "cvssV3_0": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
            "version": "3.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1333",
              "description": "CWE-1333 Inefficient Regular Expression Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-07-07T09:54:39.079Z",
        "orgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
        "shortName": "@huntr_ai"
      },
      "references": [
        {
          "url": "https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184"
        },
        {
          "url": "https://github.com/huggingface/transformers/commit/0720e206c6ba28887e4d60ef60a6a089f6c1cc76"
        }
      ],
      "source": {
        "advisory": "ecf5ccc4-39e7-4fb3-b547-14a41d31a184",
        "discovery": "EXTERNAL"
      },
      "title": "Regular Expression Denial of Service (ReDoS) in huggingface/transformers"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
    "assignerShortName": "@huntr_ai",
    "cveId": "CVE-2025-3262",
    "datePublished": "2025-07-07T09:54:39.079Z",
    "dateReserved": "2025-04-04T12:40:28.677Z",
    "dateUpdated": "2025-07-07T15:19:42.413Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

GHSA-489J-G2VX-39WF

Vulnerability from github – Published: 2025-07-07 12:30 – Updated: 2025-08-04 15:29

Summary

Transformers vulnerable to ReDoS attack through its SETTING_RE variable

Details

Severity

5.3 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "transformers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.49.0"
            },
            {
              "fixed": "4.51.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-3262"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1333"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-07-07T23:44:56Z",
    "nvd_published_at": "2025-07-07T10:15:27Z",
    "severity": "MODERATE"
  },
  "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 \u0027almost matching\u0027 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.",
  "id": "GHSA-489j-g2vx-39wf",
  "modified": "2025-08-04T15:29:18Z",
  "published": "2025-07-07T12:30:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-3262"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/transformers/commit/0720e206c6ba28887e4d60ef60a6a089f6c1cc76"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/transformers/commit/126abe3461762e5fc180e7e614391d1b4ab051ca"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/huggingface/transformers"
    },
    {
      "type": "WEB",
      "url": "https://huntr.com/bounties/ecf5ccc4-39e7-4fb3-b547-14a41d31a184"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Transformers vulnerable to ReDoS attack through its SETTING_RE variable"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

PYSEC-2026-1979

CVE-2025-3262 (GCVE-0-2025-3262)

GHSA-489J-G2VX-39WF

Tags

Sightings

Nomenclature