{
  "cveId": "CVE-2026-34831",
  "url": "https://patchblox.com/security/cve/CVE-2026-34831",
  "summary": "CVE-2026-34831 is fixed in 2 products 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: Routine.",
  "title": "ruby-rack: Rack is a modular Ruby web server interface",
  "description": "Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Files#fail sets the Content-Length response header using String#size instead of String#bytesize. When the response body contains multibyte UTF-8 characters, the declared Content-Length is smaller than the number of bytes actually sent on the wire. Because Rack::Files reflects the requested path in 404 responses, an attacker can trigger this mismatch by requesting a non-existent path containing percent-encoded UTF-8 characters. This results in incorrect HTTP response framing and may cause response desynchronization in deployments that rely on the incorrect Content-Length value. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.",
  "published": "2026-04-02T10:16:00Z",
  "severity": "medium",
  "cvss": 6.5,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
  "epss": 0.00152,
  "epssPercentile": 0.04428,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "rmt-server",
      "release": "opensuse-leap 16.0",
      "fixedVersion": "3.1.0-160000.1.1",
      "fix": "OPENSUSE-SU-2026:21640-1",
      "url": "https://patchblox.com/security/fix/linux/opensuse-su-2026-21640-1",
      "released": "2026-08-25T06:34:56Z"
    },
    {
      "platform": "linux",
      "product": "rmt-server",
      "release": "sles 15.6",
      "fixedVersion": "2.27-150500.3.47.1",
      "fix": "SUSE-SU-2026:2487-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-2487-1",
      "released": "2026-06-22T12:08:31Z"
    },
    {
      "platform": "linux",
      "product": "rmt-server",
      "release": "sles 16.0",
      "fixedVersion": "3.1.0-160000.1.1",
      "fix": "SUSE-SU-2026:23321-1",
      "url": "https://patchblox.com/security/fix/linux/suse-su-2026-23321-1",
      "released": "2026-08-25T06:34:19Z"
    },
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "2.2.22-0\u002Bdeb12u2",
      "fix": "DEBIAN-CVE-2026-34831",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-34831",
      "released": "2026-04-02T17:16:26Z"
    },
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "3.1.20-0\u002Bdeb13u2",
      "fix": "DEBIAN-CVE-2026-34831",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-34831",
      "released": "2026-04-02T17:16:26Z"
    },
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Debian 14",
      "fixedVersion": "3.2.6-2",
      "fix": "DEBIAN-CVE-2026-34831",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-34831",
      "released": "2026-04-02T17:16:26Z"
    },
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Ubuntu 22.04.1 LTS (jammy)",
      "fixedVersion": "2.1.4-5ubuntu1.2\u002Besm3",
      "fix": "ruby-rack 2.1.4-5ubuntu1.2\u002Besm3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-jammy-ruby-rack-2.1.4-5ubuntu1.2-esm3",
      "released": "2026-04-30T14:06:06Z"
    },
    {
      "platform": "linux",
      "product": "ruby-rack",
      "release": "Ubuntu 24.04.5 LTS (noble)",
      "fixedVersion": "2.2.7-1ubuntu0.7",
      "fix": "ruby-rack 2.2.7-1ubuntu0.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-noble-ruby-rack-2.2.7-1ubuntu0.7",
      "released": "2026-04-30T14:06:10Z"
    },
    {
      "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": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}