{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "0"
                  },
                  {
                    "fixed": "3.14.4"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "fixed": "8c8906a19f64e52ef6a7d44d65217eb3c5af413f"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "range": [
                  {
                    "fixed": "8cfbe9abe5e11b84006a10f9bdf82bf607671dab"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "original_tag": "v3.14.4",
                "range": [
                  {
                    "fixed": "0c5e5e1c2256c2f46fa83912d01df7632c3b26cd"
                  }
                ],
                "source": "REFERENCES_TAG"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0c5e5e1c2256c2f46fa83912d01df7632c3b26cd"
            },
            {
              "fixed": "8c8906a19f64e52ef6a7d44d65217eb3c5af413f"
            },
            {
              "fixed": "8cfbe9abe5e11b84006a10f9bdf82bf607671dab"
            }
          ],
          "repo": "https://github.com/aio-libs/aiohttp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-3rp8-rxj8-mvjw"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/128xxx/CVE-2026-128128.json"
  },
  "details": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, the C WebSocket reader adds a declared frame length to the size of an already buffered partial message using signed 64-bit arithmetic. A length near two to the power of 63 can overflow, allowing the max_msg_size check to pass. A remote peer can send a small non-final fragment followed by an oversized message and cause unbounded memory consumption. The Python WebSocket reader is unaffected. This issue is fixed in version 3.14.4.",
  "id": "CVE-2026-128128",
  "modified": "2026-11-14T10:30:43.194725480Z",
  "published": "2026-11-13T20:31:59.981Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/128xxx/CVE-2026-128128.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/commit/8c8906a19f64e52ef6a7d44d65217eb3c5af413f"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/commit/8cfbe9abe5e11b84006a10f9bdf82bf607671dab"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/pull/13415"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/pull/13494"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3rp8-rxj8-mvjw"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-128128"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "AIOHTTP: WebSocket max_msg_size bypass via integer overflow"
}