AIOHTTP: Unread Compressed Request Bodies Bypass client_max_size During Cleanup

{
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "cveMetadata": {
    "cveId": "CVE-2026-54278",
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "dateUpdated": "2026-06-22T16:38:38.838Z",
    "dateReserved": "2026-06-12T17:13:32.280Z",
    "datePublished": "2026-06-22T16:38:38.838Z",
    "state": "PUBLISHED"
  },
  "containers": {
    "cna": {
      "providerMetadata": {
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M",
        "dateUpdated": "2026-06-22T16:38:38.838Z"
      },
      "title": "AIOHTTP: Unread Compressed Request Bodies Bypass client_max_size During Cleanup",
      "descriptions": [
        {
          "lang": "en",
          "value": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, during cleanup it is possible for a compressed request body to be decompressed into memory in one chunk. An attacker may be able to send a compressed payload in specific situations that could be decompressed into memory, potentially leading to DoS (a zip bomb edge case). This vulnerability is fixed in 3.14.1."
        }
      ],
      "affected": [
        {
          "vendor": "aio-libs",
          "product": "aiohttp",
          "versions": [
            {
              "version": "< 3.14.1",
              "status": "affected"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "lang": "en",
              "description": "CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)",
              "cweId": "CWE-409",
              "type": "CWE"
            }
          ]
        }
      ],
      "references": [
        {
          "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-g3cq-j2xw-wf74",
          "name": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-g3cq-j2xw-wf74",
          "tags": [
            "x_refsource_CONFIRM"
          ]
        },
        {
          "url": "https://github.com/aio-libs/aiohttp/commit/4f7480e474cccc6a8cc2c92ad3f17a31dedf8232",
          "name": "https://github.com/aio-libs/aiohttp/commit/4f7480e474cccc6a8cc2c92ad3f17a31dedf8232",
          "tags": [
            "x_refsource_MISC"
          ]
        }
      ],
      "metrics": [
        {}
      ]
    }
  }
}