{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "1.10.3"
              },
              {
                "fixed": "2.8.0"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "0b744993bbe30fe6e3e4e0c93416412d8e598301"
            },
            {
              "fixed": "b1d30ab61fe0db8f11092805e8c5ac43e091064a"
            }
          ],
          "repo": "https://github.com/urllib3/urllib3",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-vxq7-64xx-v4gw"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97689.json"
  },
  "details": "urllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newline or EOF without a length bound. The trigger is that a malicious server returns Transfer-Encoding: chunked followed by a very long run of bytes without a newline. The attack mechanism is that a malicious HTTP server sends a very long unterminated chunk-size line. The impact is that unbounded memory allocation can exhaust the client process. This issue is fixed in version 2.8.0.",
  "id": "CVE-2026-97689",
  "modified": "2026-09-30T03:30:21.722393796Z",
  "published": "2026-09-29T15:36:05.963Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97689.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/urllib3/urllib3/commit/cd770b059b543be29298ea5c52afb0b1b090f5ed"
    },
    {
      "type": "WEB",
      "url": "https://github.com/urllib3/urllib3/releases/tag/2.8.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/urllib3/urllib3/security/advisories/GHSA-vxq7-64xx-v4gw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97689"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H",
      "type": "CVSS_V4"
    }
  ],
  "summary": "urllib3: HTTPResponse.stream()/read_chunked() buffers an unbounded chunk-size line into memory"
}