{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.1.0"
              },
              {
                "fixed": "1.9.3"
              }
            ],
            "source": [
              "DESCRIPTION",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "47889857fb36f07606ad9c2e52080d202d419058"
            },
            {
              "fixed": "f0b72c0b2363c98d0a220019d108ac6141715428"
            },
            {
              "fixed": "fc7d16538db7e40b56ed489f08683225cb0197fa"
            }
          ],
          "repo": "https://github.com/elixir-mint/mint",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-x3x7-96vm-6h2w"
  ],
  "database_specific": {
    "cna_assigner": "EEF",
    "cwe_ids": [
      "CWE-444"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59249.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "introduced": "60089586ec7adc9fddb09f69a2f5919ba9ac7f33"
          },
          {
            "fixed": "fc7d16538db7e40b56ed489f08683225cb0197fa"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "Inconsistent interpretation of HTTP requests (HTTP response smuggling) vulnerability in elixir-mint mint allows a malicious HTTP/1 server to desynchronize a strict intermediary and the Mint client on the same pooled connection, enabling response-queue poisoning against subsequent requests that share the connection.\n\nThe Mint.HTTP1.decode_body/5 function in lib/mint/http1.ex parses the chunk-size line of a Transfer-Encoding: chunked response with Integer.parse(data, 16). RFC 7230 defines chunk-size = 1*HEXDIG and forbids any sign prefix, but Integer.parse/2 accepts an optional leading + or -. A chunk-size line of +5 is accepted as a five-byte chunk; lines of +0 and -0 are accepted as the terminating zero-length chunk and end the message body early.\n\nAn RFC-strict intermediary in the response path rejects these forms, so the intermediary and the Mint client disagree on where one response ends and the next begins. On a pooled keep-alive connection, an attacker-influenced origin can inject bytes that the client attributes to the next legitimate response on the same connection, poisoning the response queue and corrupting the responses returned to unrelated in-flight requests.\n\nThis issue affects mint: from 0.1.0 before 1.9.3.",
  "id": "CVE-2026-59249",
  "modified": "2026-08-07T11:31:10.971706169Z",
  "published": "2026-07-16T11:39:29.939Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-59249.html"
    },
    {
      "type": "WEB",
      "url": "https://github.com"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-59249"
    },
    {
      "type": "WEB",
      "url": "https://repo.hex.pm"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59249.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/elixir-mint/mint/security/advisories/GHSA-x3x7-96vm-6h2w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59249"
    },
    {
      "type": "FIX",
      "url": "https://github.com/elixir-mint/mint/commit/fc7d16538db7e40b56ed489f08683225cb0197fa"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/elixir-mint/mint"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Sign-tolerant HTTP/1 chunk-size parser in Mint enables response smuggling against strict intermediaries on pooled connections"
}