FKIE_CVE-2026-34230

Vulnerability from fkie_nvd - Published: 2026-04-02 17:16 - Updated: 2026-07-24 21:10
Severity
5.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.select_best_encoding processes Accept-Encoding values with quadratic time complexity when the header contains many wildcard (*) entries. Because this method is used by Rack::Deflater to choose a response encoding, an unauthenticated attacker can send a single request with a crafted Accept-Encoding header and cause disproportionate CPU consumption on the compression middleware path. This results in a denial of service condition for applications using Rack::Deflater. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.
References
security-advisories@github.comhttps://github.com/rack/rack/security/advisories/GHSA-v569-hp3g-36wrVendor Advisory
Impacted products
Vendor Product Version
rack rack *
rack rack *
rack rack *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "rack",
          "vendor": "rack",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.2.23"
            },
            {
              "status": "affected",
              "version": "\u003e= 3.0.0.beta1, \u003c 3.1.21"
            },
            {
              "status": "affected",
              "version": "\u003e= 3.2.0, \u003c 3.2.6"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "AD5DE7DE-3A8B-4064-A7D5-1E117A101E81",
              "versionEndExcluding": "2.2.23",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "6948AAA6-873D-46BA-AA22-4C81138128E1",
              "versionEndExcluding": "3.1.21",
              "versionStartIncluding": "3.0.0",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*",
              "matchCriteriaId": "3FB592AD-E826-49BE-AC6D-E5F55FDCC96E",
              "versionEndExcluding": "3.2.6",
              "versionStartIncluding": "3.2.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.select_best_encoding processes Accept-Encoding values with quadratic time complexity when the header contains many wildcard (*) entries. Because this method is used by Rack::Deflater to choose a response encoding, an unauthenticated attacker can send a single request with a crafted Accept-Encoding header and cause disproportionate CPU consumption on the compression middleware path. This results in a denial of service condition for applications using Rack::Deflater. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6."
    },
    {
      "lang": "es",
      "value": "Rack es una interfaz modular de servidor web Ruby. Antes de las versiones 2.2.23, 3.1.21 y 3.2.6, Rack::Utils.select_best_encoding procesa los valores de Accept-Encoding con complejidad de tiempo cuadr\u00e1tica cuando el encabezado contiene muchas entradas de comod\u00edn (*). Debido a que este m\u00e9todo es utilizado por Rack::Deflater para elegir una codificaci\u00f3n de respuesta, un atacante no autenticado puede enviar una \u00fanica solicitud con un encabezado Accept-Encoding manipulado y causar un consumo desproporcionado de CPU en la ruta del middleware de compresi\u00f3n. Esto resulta en una condici\u00f3n de denegaci\u00f3n de servicio para aplicaciones que utilizan Rack::Deflater. Este problema ha sido parcheado en las versiones 2.2.23, 3.1.21 y 3.2.6."
    }
  ],
  "id": "CVE-2026-34230",
  "lastModified": "2026-07-24T21:10:00.143",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "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:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "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"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-34230",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-04-02T18:56:03.220311Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-04-02T17:16:23.570",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Vendor Advisory"
      ],
      "url": "https://github.com/rack/rack/security/advisories/GHSA-v569-hp3g-36wr"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        },
        {
          "lang": "en",
          "value": "CWE-407"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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