Common Weakness Enumeration

CWE-400

Discouraged

Uncontrolled Resource Consumption

Abstraction: Class · Status: Draft

The product does not properly control the allocation and maintenance of a limited resource.

5412 vulnerabilities reference this CWE, most recent first.

GHSA-V6G3-9679-C8VH

Vulnerability from github – Published: 2022-05-24 17:19 – Updated: 2022-05-24 17:19
VLAI
Details

An issue was discovered in Foxit PhantomPDF before 8.3.12. It allows stack consumption via nested function calls for XML parsing.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2019-20815"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2020-06-04T16:15:00Z",
    "severity": "MODERATE"
  },
  "details": "An issue was discovered in Foxit PhantomPDF before 8.3.12. It allows stack consumption via nested function calls for XML parsing.",
  "id": "GHSA-v6g3-9679-c8vh",
  "modified": "2022-05-24T17:19:13Z",
  "published": "2022-05-24T17:19:13Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2019-20815"
    },
    {
      "type": "WEB",
      "url": "https://www.foxitsoftware.com/support/security-bulletins.php"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

GHSA-V6H2-P8H4-QCJW

Vulnerability from github – Published: 2025-06-09 21:30 – Updated: 2025-06-11 20:54
VLAI
Summary
brace-expansion Regular Expression Denial of Service vulnerability
Details

A vulnerability was found in juliangruber brace-expansion up to 1.1.11/2.0.1/3.0.0/4.0.0. It has been rated as problematic. Affected by this issue is the function expand of the file index.js. The manipulation leads to inefficient regular expression complexity. The attack may be launched remotely. The complexity of an attack is rather high. The exploitation is known to be difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 1.1.12, 2.0.2, 3.0.1 and 4.0.1 is able to address this issue. The name of the patch is a5b98a4f30d7813266b221435e1eaaf25a1b0ac5. It is recommended to upgrade the affected component.

Show details on source website

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.0.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "brace-expansion"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.1.11"
      },
      "package": {
        "ecosystem": "npm",
        "name": "brace-expansion"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.0.0"
            },
            {
              "fixed": "1.1.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "brace-expansion"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.0.0"
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "brace-expansion"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.0.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2025-5889"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-06-10T22:51:59Z",
    "nvd_published_at": "2025-06-09T19:15:25Z",
    "severity": "LOW"
  },
  "details": "A vulnerability was found in juliangruber brace-expansion up to 1.1.11/2.0.1/3.0.0/4.0.0. It has been rated as problematic. Affected by this issue is the function expand of the file index.js. The manipulation leads to inefficient regular expression complexity. The attack may be launched remotely. The complexity of an attack is rather high. The exploitation is known to be difficult. The exploit has been disclosed to the public and may be used. Upgrading to version 1.1.12, 2.0.2, 3.0.1 and 4.0.1 is able to address this issue. The name of the patch is `a5b98a4f30d7813266b221435e1eaaf25a1b0ac5`. It is recommended to upgrade the affected component.",
  "id": "GHSA-v6h2-p8h4-qcjw",
  "modified": "2025-06-11T20:54:10Z",
  "published": "2025-06-09T21:30:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-5889"
    },
    {
      "type": "WEB",
      "url": "https://github.com/juliangruber/brace-expansion/pull/65/commits/a5b98a4f30d7813266b221435e1eaaf25a1b0ac5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/juliangruber/brace-expansion/commit/0b6a9781e18e9d2769bb2931f4856d1360243ed2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/juliangruber/brace-expansion/commit/15f9b3c75ebf5988198241fecaebdc45eff28a9f"
    },
    {
      "type": "WEB",
      "url": "https://github.com/juliangruber/brace-expansion/commit/36603d5f3599a37af9e85eda30acd7d28599c36e"
    },
    {
      "type": "WEB",
      "url": "https://github.com/juliangruber/brace-expansion/commit/c3c73c8b088defc70851843be88ccc3af08e7217"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/mmmsssttt404/37a40ce7d6e5ca604858fe30814d9466"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/juliangruber/brace-expansion"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?ctiid.311660"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?id.311660"
    },
    {
      "type": "WEB",
      "url": "https://vuldb.com/?submit.585717"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ],
  "summary": "brace-expansion Regular Expression Denial of Service vulnerability"
}

GHSA-V6J3-7JRW-HQ2P

Vulnerability from github – Published: 2022-05-17 04:59 – Updated: 2023-08-25 23:09
VLAI
Summary
Rack Gem Subject to Denial of Service via Hash Collisions
Details

Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "rack"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "rack"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.2.0"
            },
            {
              "fixed": "1.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "rack"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.3.0"
            },
            {
              "fixed": "1.3.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.jruby:jruby-parent"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.6.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2011-5036"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-328",
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-03-27T16:12:55Z",
    "nvd_published_at": "2011-12-30T01:55:00Z",
    "severity": "MODERATE"
  },
  "details": "Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.",
  "id": "GHSA-v6j3-7jrw-hq2p",
  "modified": "2023-08-25T23:09:49Z",
  "published": "2022-05-17T04:59:13Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2011-5036"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/52bbc6b9cc19ce330829"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2011-5036.yml"
    },
    {
      "type": "WEB",
      "url": "https://web.archive.org/web/20120201040317/http://jruby.org/2011/12/27/jruby-1-6-5-1"
    },
    {
      "type": "WEB",
      "url": "https://web.archive.org/web/20130213132312/http://archives.neohapsis.com/archives/bugtraq/2011-12/0181.html"
    },
    {
      "type": "WEB",
      "url": "http://www.debian.org/security/2013/dsa-2783"
    },
    {
      "type": "WEB",
      "url": "http://www.kb.cert.org/vuls/id/903934"
    },
    {
      "type": "WEB",
      "url": "http://www.nruns.com/_downloads/advisory28122011.pdf"
    },
    {
      "type": "WEB",
      "url": "http://www.ocert.org/advisories/ocert-2011-003.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [],
  "summary": "Rack Gem Subject to Denial of Service via Hash Collisions"
}

GHSA-V6MH-52Q2-XJGF

Vulnerability from github – Published: 2022-05-12 00:02 – Updated: 2022-05-19 00:00
VLAI
Details

Asus DSL-N14U-B1 1.1.2.3_805 allows remote attackers to cause a Denial of Service (DoS) via a TCP SYN scan using nmap.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2021-3254"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2022-05-11T12:15:00Z",
    "severity": "HIGH"
  },
  "details": "Asus DSL-N14U-B1 1.1.2.3_805 allows remote attackers to cause a Denial of Service (DoS) via a TCP SYN scan using nmap.",
  "id": "GHSA-v6mh-52q2-xjgf",
  "modified": "2022-05-19T00:00:17Z",
  "published": "2022-05-12T00:02:04Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-3254"
    },
    {
      "type": "WEB",
      "url": "https://github.com/kaisersource/kaisersource.github.io/blob/main/_posts/2021-01-22-dsl-n14u.md"
    },
    {
      "type": "WEB",
      "url": "https://kaisersource.github.io/dsl-n14u-syn"
    }
  ],
  "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:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V6MW-4FWV-QVR5

Vulnerability from github – Published: 2025-07-04 18:30 – Updated: 2025-07-08 18:31
VLAI
Details

Uncontrolled Resource Consumption vulnerability in Wikimedia Foundation Mediawiki - IPInfo Extension allows Excessive Allocation.This issue affects Mediawiki - IPInfo Extension: from 1.39.X before 1.39.13, from 1.42.X before 1.42.7, from 1.43.X before 1.43.2.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2025-53481"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-07-04T16:15:22Z",
    "severity": "HIGH"
  },
  "details": "Uncontrolled Resource Consumption vulnerability in Wikimedia Foundation Mediawiki - IPInfo Extension allows Excessive Allocation.This issue affects Mediawiki - IPInfo Extension: from 1.39.X before 1.39.13, from 1.42.X before 1.42.7, from 1.43.X before 1.43.2.",
  "id": "GHSA-v6mw-4fwv-qvr5",
  "modified": "2025-07-08T18:31:06Z",
  "published": "2025-07-04T18:30:56Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-53481"
    },
    {
      "type": "WEB",
      "url": "https://gerrit.wikimedia.org/r/q/I08a7154f8fa08bb6f0940e522075bdc2a3d4433f"
    },
    {
      "type": "WEB",
      "url": "https://gerrit.wikimedia.org/r/q/I474b7a1b3bc1e7597fee0826a18a0cf042359f0f"
    },
    {
      "type": "WEB",
      "url": "https://phabricator.wikimedia.org/T392976"
    }
  ],
  "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:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V6Q2-VRQ7-XPRQ

Vulnerability from github – Published: 2022-05-14 03:19 – Updated: 2022-05-14 03:19
VLAI
Details

LiteCart before 2.1.2 allows remote attackers to cause a denial of service (memory consumption) via URIs that do not exist, because public_html/logs/not_found.log grows without bound, and is loaded into memory for each request.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2018-10827"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2018-05-09T04:29:00Z",
    "severity": "HIGH"
  },
  "details": "LiteCart before 2.1.2 allows remote attackers to cause a denial of service (memory consumption) via URIs that do not exist, because public_html/logs/not_found.log grows without bound, and is loaded into memory for each request.",
  "id": "GHSA-v6q2-vrq7-xprq",
  "modified": "2022-05-14T03:19:26Z",
  "published": "2022-05-14T03:19:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-10827"
    },
    {
      "type": "WEB",
      "url": "https://github.com/litecart/litecart/issues/119"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V6RC-PPGP-5PMR

Vulnerability from github – Published: 2023-04-02 21:30 – Updated: 2023-04-07 21:30
VLAI
Details

Uncontrolled resource consumption in the logging feature in Devolutions Gateway 2023.1.1 and earlier allows an attacker to cause a denial of service by filling up the disk and render the system unusable.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2023-1580"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-04-02T21:15:00Z",
    "severity": "HIGH"
  },
  "details": "Uncontrolled resource consumption in the logging feature in Devolutions Gateway 2023.1.1 and earlier allows an attacker to cause a denial of service by filling up the disk and render the system unusable.",
  "id": "GHSA-v6rc-ppgp-5pmr",
  "modified": "2023-04-07T21:30:15Z",
  "published": "2023-04-02T21:30:17Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-1580"
    },
    {
      "type": "WEB",
      "url": "https://devolutions.net/security/advisories/DEVO-2023-0007"
    }
  ],
  "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:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V6RH-VJ3X-WP5C

Vulnerability from github – Published: 2023-08-14 18:32 – Updated: 2024-04-04 06:55
VLAI
Details

IBM TXSeries for Multiplatforms 8.1, 8.2, and 9.1 is vulnerable to a denial of service, caused by improper enforcement of the timeout on individual read operations. By conducting a slowloris-type attacks, a remote attacker could exploit this vulnerability to cause a denial of service. IBM X-Force ID: 262905.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2023-38741"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2023-08-14T18:15:11Z",
    "severity": "HIGH"
  },
  "details": "\nIBM TXSeries for Multiplatforms 8.1, 8.2, and 9.1 is vulnerable to a denial of service, caused by improper enforcement of the timeout on individual read operations. By conducting a slowloris-type attacks, a remote attacker could exploit this vulnerability to cause a denial of service. IBM X-Force ID: 262905.\n\n",
  "id": "GHSA-v6rh-vj3x-wp5c",
  "modified": "2024-04-04T06:55:12Z",
  "published": "2023-08-14T18:32:59Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-38741"
    },
    {
      "type": "WEB",
      "url": "https://exchange.xforce.ibmcloud.com/vulnerabilities/262905"
    },
    {
      "type": "WEB",
      "url": "https://www.ibm.com/support/pages/node/7025476"
    }
  ],
  "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:H",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-V6WH-2WVH-C8X5

Vulnerability from github – Published: 2022-02-09 23:15 – Updated: 2023-09-11 23:10
VLAI
Summary
Regular Expression Denial of Service in djvalidator
Details

All versions of package djvalidator are vulnerable to Regular Expression Denial of Service (ReDoS) by sending crafted invalid emails - for example, --@------------------------------------------------------------------------------------------------------------------------!.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "djvalidator"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "1.1.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2020-7779"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-04-13T18:54:11Z",
    "nvd_published_at": "2020-11-26T11:15:00Z",
    "severity": "HIGH"
  },
  "details": "All versions of package djvalidator are vulnerable to Regular Expression Denial of Service (ReDoS) by sending crafted invalid emails - for example, \n`--@------------------------------------------------------------------------------------------------------------------------!`.",
  "id": "GHSA-v6wh-2wvh-c8x5",
  "modified": "2023-09-11T23:10:32Z",
  "published": "2022-02-09T23:15:46Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-7779"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JS-DJVALIDATOR-1018709"
    }
  ],
  "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:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Regular Expression Denial of Service in djvalidator"
}

GHSA-V6X5-CG8R-VV6X

Vulnerability from github – Published: 2026-04-02 20:30 – Updated: 2026-05-13 16:18
VLAI
Summary
Rack's multipart header parsing allows Denial of Service via escape-heavy quoted parameters
Details

Summary

Rack::Multipart::Parser#handle_mime_head parses quoted multipart parameters such as Content-Disposition: form-data; name="..." using repeated String#index searches combined with String#slice! prefix deletion. For escape-heavy quoted values, this causes super-linear processing.

An unauthenticated attacker can send a crafted multipart/form-data request containing many parts with long backslash-escaped parameter values to trigger excessive CPU usage during multipart parsing.

This results in a denial of service condition in Rack applications that accept multipart form data.

Details

Rack::Multipart::Parser#handle_mime_head parses quoted parameter values by repeatedly:

  1. Searching for the next quote or backslash,
  2. Copying the preceding substring into a new buffer, and
  3. Removing the processed prefix from the original string with slice!.

An attacker can exploit this by sending a multipart request with many parts whose name parameters contain long escape-heavy values such as:

name="a\\a\\a\\a\\a\\..."

Under default Rack limits, a request can contain up to 4095 parts. If many of those parts use long quoted values with dense escape characters, the parser performs disproportionately expensive CPU work while remaining within normal request size and part-count limits.

Impact

Any Rack application that accepts multipart/form-data requests may be affected, including file upload endpoints and standard HTML form handlers.

An unauthenticated attacker can send crafted multipart requests that consume excessive CPU time during request parsing. Repeated requests can tie up application workers, reduce throughput, and degrade or deny service availability.

Mitigation

  • Update to a patched version of Rack that parses quoted multipart parameters without repeated rescanning and destructive prefix deletion.
  • Apply request throttling or rate limiting to multipart upload endpoints.
  • Where operationally feasible, restrict or isolate multipart parsing on untrusted high-volume endpoints.
Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "rack"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0.beta1"
            },
            {
              "fixed": "3.1.21"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "rack"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.2.0"
            },
            {
              "fixed": "3.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-34827"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400",
      "CWE-407",
      "CWE-770"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-02T20:30:12Z",
    "nvd_published_at": "2026-04-02T18:16:33Z",
    "severity": "HIGH"
  },
  "details": "## Summary\n\n`Rack::Multipart::Parser#handle_mime_head` parses quoted multipart parameters such as `Content-Disposition: form-data; name=\"...\"` using repeated `String#index` searches combined with `String#slice!` prefix deletion. For escape-heavy quoted values, this causes super-linear processing.\n\nAn unauthenticated attacker can send a crafted `multipart/form-data` request containing many parts with long backslash-escaped parameter values to trigger excessive CPU usage during multipart parsing.\n\nThis results in a denial of service condition in Rack applications that accept multipart form data.\n\n## Details\n\n`Rack::Multipart::Parser#handle_mime_head` parses quoted parameter values by repeatedly:\n\n1. Searching for the next quote or backslash,\n2. Copying the preceding substring into a new buffer, and\n3. Removing the processed prefix from the original string with `slice!`.\n\nAn attacker can exploit this by sending a multipart request with many parts whose `name` parameters contain long escape-heavy values such as:\n\n```text\nname=\"a\\\\a\\\\a\\\\a\\\\a\\\\...\"\n```\n\nUnder default Rack limits, a request can contain up to 4095 parts. If many of those parts use long quoted values with dense escape characters, the parser performs disproportionately expensive CPU work while remaining within normal request size and part-count limits.\n\n## Impact\n\nAny Rack application that accepts `multipart/form-data` requests may be affected, including file upload endpoints and standard HTML form handlers.\n\nAn unauthenticated attacker can send crafted multipart requests that consume excessive CPU time during request parsing. Repeated requests can tie up application workers, reduce throughput, and degrade or deny service availability.\n\n## Mitigation\n\n* Update to a patched version of Rack that parses quoted multipart parameters without repeated rescanning and destructive prefix deletion.\n* Apply request throttling or rate limiting to multipart upload endpoints.\n* Where operationally feasible, restrict or isolate multipart parsing on untrusted high-volume endpoints.",
  "id": "GHSA-v6x5-cg8r-vv6x",
  "modified": "2026-05-13T16:18:33Z",
  "published": "2026-04-02T20:30:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/rack/rack/security/advisories/GHSA-v6x5-cg8r-vv6x"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34827"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/rack/rack"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2026-34827.yml"
    }
  ],
  "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:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Rack\u0027s multipart header parsing allows Denial of Service via escape-heavy quoted parameters"
}

Mitigation
Architecture and Design

Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.

Mitigation
Architecture and Design
  • Mitigation of resource exhaustion attacks requires that the target system either:
  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
  • The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
  • recognizes the attack and denies that user further access for a given amount of time, or
  • uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Mitigation
Architecture and Design

Ensure that protocols have specific limits of scale placed on them.

Mitigation
Implementation

Ensure that all failures in resource allocation place the system into a safe posture.

CAPEC-147: XML Ping of the Death

An attacker initiates a resource depletion attack where a large number of small XML messages are delivered at a sufficiently rapid rate to cause a denial of service or crash of the target. Transactions such as repetitive SOAP transactions can deplete resources faster than a simple flooding attack because of the additional resources used by the SOAP protocol and the resources necessary to process SOAP messages. The transactions used are immaterial as long as they cause resource utilization on the target. In other words, this is a normal flooding attack augmented by using messages that will require extra processing on the target.

CAPEC-227: Sustained Client Engagement

An adversary attempts to deny legitimate users access to a resource by continually engaging a specific resource in an attempt to keep the resource tied up as long as possible. The adversary's primary goal is not to crash or flood the target, which would alert defenders; rather it is to repeatedly perform actions or abuse algorithmic flaws such that a given resource is tied up and not available to a legitimate user. By carefully crafting a requests that keep the resource engaged through what is seemingly benign requests, legitimate users are limited or completely denied access to the resource.

CAPEC-492: Regular Expression Exponential Blowup

An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.