{
  "cveId": "CVE-2026-34827",
  "url": "https://patchblox.com/security/cve/CVE-2026-34827",
  "summary": "CVE-2026-34827 is fixed in ruby-rack on 1 platform, first by ruby-rack 3.2.4-1ubuntu1.1, released April 2, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "ruby-rack: Rack is a modular Ruby web server interface",
  "description": "Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21, and 3.2.0 to before 3.2.6, Rack::Multipart::Parser#handle_mime_head parses quoted multipart parameters such as Content-Disposition: form-data; name=\u0022...\u0022 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. This issue has been patched in versions 3.1.21 and 3.2.6.",
  "published": "2026-04-02T11:16:00Z",
  "severity": "high",
  "cvss": 7.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00494,
  "epssPercentile": 0.42656,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "3.1.20-0\u002Bdeb13u2",
      "fix": "DEBIAN-CVE-2026-34827",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-34827",
      "released": "2026-04-02T18:16:33Z"
    },
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Debian 14",
      "fixedVersion": "3.2.6-2",
      "fix": "DEBIAN-CVE-2026-34827",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-34827",
      "released": "2026-04-02T18:16:33Z"
    },
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Ubuntu 25.10 (questing)",
      "fixedVersion": "3.1.16-0.1ubuntu0.3",
      "fix": "ruby-rack 3.1.16-0.1ubuntu0.3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-questing-ruby-rack-3.1.16-0.1ubuntu0.3",
      "released": "2026-04-30T14:06:15Z"
    },
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "3.2.4-1ubuntu1.1",
      "fix": "ruby-rack 3.2.4-1ubuntu1.1",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-ruby-rack-3.2.4-1ubuntu1.1",
      "released": "2026-04-02T11:16:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}