{
  "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": "53b35a2f8869c37a133e60bf1a82a1c01642ba2b"
            }
          ],
          "repo": "https://github.com/aio-libs/aiohttp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-mwh4-6h8g-pg8w"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-113"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34519.json"
  },
  "details": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, an attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits. This issue has been patched in version 3.13.4.",
  "id": "CVE-2026-34519",
  "modified": "2026-07-15T01:48:56.939746359Z",
  "published": "2026-04-01T20:26:25.553Z",
  "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-2026-34519.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mwh4-6h8g-pg8w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34519"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642ba2b"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "AIOHTTP: HTTP response splitting via \\r in reason phrase"
}