{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "2.2.23"
              },
              {
                "introduced": "3.0.0"
              },
              {
                "fixed": "3.1.21"
              },
              {
                "introduced": "3.2.0"
              },
              {
                "fixed": "3.2.6"
              }
            ],
            "source": "CPE_RANGE"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "f2af0c8f869193fa7bb7d20b619b3003418e1055"
            },
            {
              "introduced": "52901caf09ebcda879512a8605059963a49df55d"
            },
            {
              "fixed": "ae8431120e66e92d1885ab8ec0a553d9cad5ec13"
            },
            {
              "introduced": "b68251c03788ff39d4a4b25424df7360426e4afd"
            },
            {
              "fixed": "e1f22fdbe99afd2126b6fbf05bb12399359574b7"
            }
          ],
          "repo": "https://github.com/rack/rack",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-8vqr-qjwx-82mw"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-400",
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34829.json"
  },
  "details": "Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Multipart::Parser only wraps the request body in a BoundedIO when CONTENT_LENGTH is present. When a multipart/form-data request is sent without a Content-Length header, such as with HTTP chunked transfer encoding, multipart parsing continues until end-of-stream with no total size limit. For file parts, the uploaded body is written directly to a temporary file on disk rather than being constrained by the buffered in-memory upload limit. An unauthenticated attacker can therefore stream an arbitrarily large multipart file upload and consume unbounded disk space. This results in a denial of service condition for Rack applications that accept multipart form data. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.",
  "id": "CVE-2026-34829",
  "modified": "2026-07-15T01:49:19.217586982Z",
  "published": "2026-04-02T16:46:47.357Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34829.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/security/cve/CVE-2026-34829"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34829.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/rack/rack/security/advisories/GHSA-8vqr-qjwx-82mw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34829"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2454488"
    }
  ],
  "schema_version": "1.8.0",
  "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: Denial of Service via Unbounded Multipart File Upload Without Content-Length"
}