CVE-2023-46136 (GCVE-0-2023-46136)

Vulnerability from cvelistv5 – Published: 2023-10-24 23:48 – Updated: 2026-05-20 22:17
VLAI
Title
Werkzeug vulnerable to high resource usage when parsing multipart/form-data containing a large part with CR/LF character at the beginning
Summary
Werkzeug is a comprehensive WSGI web application library. In versions on the 3.x branch prior to 3.0.1 and on the 2.x branch prior to 2.3.8, if an upload of a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. This vulnerability has been patched in version 3.0.1 and 2.3.8.
Severity
8 (High)
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE
  • CWE-407 - Inefficient Algorithmic Complexity
  • CWE-400 - Uncontrolled Resource Consumption
Assigner
References
Impacted products
Vendor Product Version
pallets werkzeug Affected: >= 3.0.0, < 3.0.1
Affected: >= 2.0.0rc1, < 2.3.8
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-02T20:37:39.469Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "name": "https://github.com/pallets/werkzeug/security/advisories/GHSA-hrfv-mqp8-q5rw",
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/pallets/werkzeug/security/advisories/GHSA-hrfv-mqp8-q5rw"
          },
          {
            "name": "https://github.com/pallets/werkzeug/commit/f3c803b3ade485a45f12b6d6617595350c0f03e2",
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/pallets/werkzeug/commit/f3c803b3ade485a45f12b6d6617595350c0f03e2"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20231124-0008/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "werkzeug",
          "vendor": "pallets",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 3.0.0, \u003c 3.0.1"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.0.0rc1, \u003c 2.3.8"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Werkzeug is a comprehensive WSGI web application library. In versions on the 3.x branch prior to 3.0.1 and on the 2.x branch prior to 2.3.8, if an upload of a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. This vulnerability has been patched in version 3.0.1 and 2.3.8."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "ADJACENT_NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-407",
              "description": "CWE-407: Inefficient Algorithmic Complexity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-20T22:17:43.259Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/pallets/werkzeug/security/advisories/GHSA-hrfv-mqp8-q5rw",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/pallets/werkzeug/security/advisories/GHSA-hrfv-mqp8-q5rw"
        },
        {
          "name": "https://github.com/pallets/werkzeug/commit/f3c803b3ade485a45f12b6d6617595350c0f03e2",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/pallets/werkzeug/commit/f3c803b3ade485a45f12b6d6617595350c0f03e2"
        }
      ],
      "source": {
        "advisory": "GHSA-hrfv-mqp8-q5rw",
        "discovery": "UNKNOWN"
      },
      "title": "Werkzeug vulnerable to high resource usage when parsing multipart/form-data containing a large part with CR/LF character at the beginning"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2023-46136",
    "datePublished": "2023-10-24T23:48:56.960Z",
    "dateReserved": "2023-10-16T17:51:35.574Z",
    "dateUpdated": "2026-05-20T22:17:43.259Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2023-46136",
      "date": "2026-10-11",
      "epss": "0.01072",
      "percentile": "0.63957"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "werkzeug",
                "vendor": "pallets",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003e= 3.0.0, \u003c 3.0.1"
                  },
                  {
                    "status": "affected",
                    "version": "\u003e= 2.0.0rc1, \u003c 2.3.8"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:palletsprojects:werkzeug:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "F6578217-312C-44C5-851E-7F6FC6C0F8C1",
                    "versionEndExcluding": "2.3.8",
                    "vulnerable": true
                  },
                  {
                    "criteria": "cpe:2.3:a:palletsprojects:werkzeug:3.0.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "3ECAF2F0-90D0-4564-93A5-0EAE8B317123",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Werkzeug is a comprehensive WSGI web application library. In versions on the 3.x branch prior to 3.0.1 and on the 2.x branch prior to 2.3.8, if an upload of a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. This vulnerability has been patched in version 3.0.1 and 2.3.8."
          },
          {
            "lang": "es",
            "value": "Werkzeug es una librer\u00eda completa de aplicaciones web WSGI. Si se carga un archivo que comienza con CR o LF y luego va seguido de megabytes de datos sin estos caracteres: todos estos bytes se agregan fragmento a fragmento en una matriz de bytes interna y la b\u00fasqueda de los l\u00edmites se realiza en un b\u00fafer en crecimiento. Esto permite a un atacante provocar una denegaci\u00f3n de servicio enviando datos multiparte manipulados a un endpoint que los analizar\u00e1. La cantidad de tiempo de CPU necesaria puede impedir que los procesos de trabajo manejen solicitudes leg\u00edtimas. Esta vulnerabilidad ha sido parcheada en la versi\u00f3n 3.0.1."
          }
        ],
        "id": "CVE-2023-46136",
        "lastModified": "2026-06-17T06:30:13.700",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "ADJACENT_NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 8.0,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.1,
              "impactScore": 5.9,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            },
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 7.5,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 3.6,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2023-10-25T18:17:36.753",
        "references": [
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Patch"
            ],
            "url": "https://github.com/pallets/werkzeug/commit/f3c803b3ade485a45f12b6d6617595350c0f03e2"
          },
          {
            "source": "security-advisories@github.com",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://github.com/pallets/werkzeug/security/advisories/GHSA-hrfv-mqp8-q5rw"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Patch"
            ],
            "url": "https://github.com/pallets/werkzeug/commit/f3c803b3ade485a45f12b6d6617595350c0f03e2"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Vendor Advisory"
            ],
            "url": "https://github.com/pallets/werkzeug/security/advisories/GHSA-hrfv-mqp8-q5rw"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20231124-0008/"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-400"
              },
              {
                "lang": "en",
                "value": "CWE-407"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Secondary"
          },
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-787"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-18T20:56:55+00:00",
      "cve": "CVE-2023-46136",
      "id": "CVE-2023-46136",
      "initial_release_date": "2023-10-25T00:00:00+00:00",
      "product_status:fixed": "35",
      "product_status:known_affected": "22",
      "product_status:known_not_affected": "413",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "python-werkzeug: high resource consumption leading to denial of service",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-46136.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-10-04T23:38:37Z",
      "cve": "CVE-2023-46136",
      "id": "CVE-2023-46136",
      "initial_release_date": "2023-10-27T00:56:12Z",
      "product_status:known_not_affected": "111",
      "product_status:recommended": "32",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2023-46136",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2023-46136.json",
      "version": "24"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.