{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "cpe": "cpe:2.3:a:aiohttp:aiohttp:*:*:*:*:*:*:*:*",
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.13.4"
              }
            ],
            "source": [
              "CPE_RANGE",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "9f7c7ab6f2924824e4a61a3b5c5c36475f4e25c6"
            },
            {
              "fixed": "53e2e6fc58b89c6185be7820bd2c9f40216b3000"
            },
            {
              "fixed": "e00ca3cca92c465c7913c4beb763a72da9ed8349"
            }
          ],
          "repo": "https://github.com/aio-libs/aiohttp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-c427-h43c-vf67"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-20",
      "CWE-444"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34525.json"
  },
  "details": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.",
  "id": "CVE-2026-34525",
  "modified": "2026-07-15T01:48:59.857952791Z",
  "published": "2026-04-01T20:28:46.652Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34525.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34525"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "AIOHTTP: Duplicate Host header accepted"
}