{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "3.14.2"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "c1b9212ad3d93c24b5fc66ad0849597166bc816e"
            },
            {
              "fixed": "47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6"
            }
          ],
          "repo": "https://github.com/aio-libs/aiohttp",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-mq44-7p77-q5h7"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-20"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59881.json"
  },
  "details": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption. This issue is fixed in version 3.14.2.",
  "id": "CVE-2026-59881",
  "modified": "2026-08-12T03:51:12.859490069Z",
  "published": "2026-07-30T17:34:32.415Z",
  "references": [
    {
      "type": "WEB",
      "url": "http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59881.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-59881"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6"
    },
    {
      "type": "FIX",
      "url": "https://github.com/aio-libs/aiohttp/pull/12978"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate"
}