{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:fastapiexpert:python-multipart:*:*:*:*:*:python:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "0.0.31"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "CPE_RANGE"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4cffc68a165f7a6f6b7756ce006fabf07a05b7a4"
            }
          ],
          "repo": "https://github.com/kludex/python-multipart",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-v9pg-7xvm-68hf"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-1284"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53540.json"
  },
  "details": "Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.31, parse_form() did not validate the Content-Length header before using it to bound its chunked read of the request body. A negative Content-Length turned the bounded read into a read-until-EOF, so the entire body was loaded into memory in a single read instead of in fixed-size chunks. This vulnerability is fixed in 0.0.31.",
  "id": "CVE-2026-53540",
  "modified": "2026-07-08T05:38:21.127119941Z",
  "published": "2026-06-22T16:58:54.923Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53540.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/Kludex/python-multipart/security/advisories/GHSA-v9pg-7xvm-68hf"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53540"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Python-Multipart: Negative Content-Length in parse_form buffers the entire body in memory"
}