CVE-2026-123817 (GCVE-0-2026-123817)

Vulnerability from cvelistv5 – Published: 2026-11-09 21:17 – Updated: 2026-11-09 21:17
VLAI
Title
AIOHTTP WebSocket frame reassembly permits excessive memory consumption from tiny reads
Summary
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, the WebSocket reader retains one bytes object for each transport read while reassembling an incomplete frame. A malicious peer can split a frame into many tiny reads so per-object overhead substantially exceeds the payload bytes allowed by max_msg_size. The condition affects a server receiving frames from a malicious client and a client receiving frames from a malicious server, and can cause excessive memory consumption or denial of service. This issue is fixed in version 3.14.4.
Severity
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CWE
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Assigner
GitHub_M CNA
References
Impacted products
Vendor Product Version
aio-libs aiohttp Affected: < 3.14.4
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "aiohttp",
          "vendor": "aio-libs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.14.4"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, the WebSocket reader retains one bytes object for each transport read while reassembling an incomplete frame. A malicious peer can split a frame into many tiny reads so per-object overhead substantially exceeds the payload bytes allowed by max_msg_size. The condition affects a server receiving frames from a malicious client and a client receiving frames from a malicious server, and can cause excessive memory consumption or denial of service. This issue is fixed in version 3.14.4."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-09T21:17:58.409Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-2g87-pp6c-29x5",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-2g87-pp6c-29x5"
        },
        {
          "name": "https://github.com/aio-libs/aiohttp/pull/13352",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/aio-libs/aiohttp/pull/13352"
        },
        {
          "name": "https://github.com/aio-libs/aiohttp/pull/13612",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/aio-libs/aiohttp/pull/13612"
        },
        {
          "name": "https://github.com/aio-libs/aiohttp/commit/09bcaa73ff084a0c539bbf16a0a78743acb7141f",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/aio-libs/aiohttp/commit/09bcaa73ff084a0c539bbf16a0a78743acb7141f"
        },
        {
          "name": "https://github.com/aio-libs/aiohttp/commit/6a4f6682817839313b04b8e5cea2b39c1a88ab4f",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/aio-libs/aiohttp/commit/6a4f6682817839313b04b8e5cea2b39c1a88ab4f"
        },
        {
          "name": "https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4"
        }
      ],
      "source": {
        "advisory": "GHSA-2g87-pp6c-29x5",
        "discovery": "UNKNOWN"
      },
      "title": "AIOHTTP WebSocket frame reassembly permits excessive memory consumption from tiny reads"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-123817",
    "datePublished": "2026-11-09T21:17:58.409Z",
    "dateReserved": "2026-11-06T15:27:56.227Z",
    "dateUpdated": "2026-11-09T21:17:58.409Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}



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