CVE-2026-123817

AIOHTTP WebSocket frame reassembly permits excessive memory consumption from tiny reads

publishedCWE-770

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.

Technical severity8.7 highCVSS 4.0 · CNA: GitHub_M

Published2026-11-09Source updated 2026-11-09

Collected2026-11-092 attributed sources

Fixes and workarounds

Fix

aiohttp (PyPI): OSV reports a fixed version 3.14.4. Check the advisory for supported release branches.

Source: OSV GHSA-2g87-pp6c-29x5

Affected products and versions

Affected products, source version ranges and reporting authorities
Product	Versions	Authority
aiohttp aio-libs	< 3.14.4 (affected)	CNA: GitHub_M
aiohttp `aiohttp` PyPI	0.1 (affected, PyPI) 0.10.0 (affected, PyPI) 0.10.1 (affected, PyPI) 0.10.2 (affected, PyPI) 0.11.0 (affected, PyPI) 0.12.0 (affected, PyPI) 0.13.0 (affected, PyPI) 0.13.1 (affected, PyPI) 0.14.0 (affected, PyPI) 0.14.1 (affected, PyPI) 0.14.2 (affected, PyPI) 0.14.3 (affected, PyPI) 0.14.4 (affected, PyPI) 0.15.0 (affected, PyPI) 0.15.1 (affected, PyPI) 0.15.2 (affected, PyPI) 0.15.3 (affected, PyPI) 0.16.0 (affected, PyPI) 0.16.1 (affected, PyPI) 0.16.2 (affected, PyPI) 0.16.3 (affected, PyPI) 0.16.4 (affected, PyPI) 0.16.5 (affected, PyPI) 0.16.6 (affected, PyPI) 0.17.0 (affected, PyPI) 0.17.1 (affected, PyPI) 0.17.2 (affected, PyPI) 0.17.3 (affected, PyPI) 0.17.4 (affected, PyPI) 0.18.0 (affected, PyPI) 0.18.1 (affected, PyPI) 0.18.2 (affected, PyPI) 0.18.3 (affected, PyPI) 0.18.4 (affected, PyPI) 0.19.0 (affected, PyPI) 0.2 (affected, PyPI) 0.20.0 (affected, PyPI) 0.20.1 (affected, PyPI) 0.20.2 (affected, PyPI) 0.21.0 (affected, PyPI) 0.21.1 (affected, PyPI) 0.21.2 (affected, PyPI) 0.21.4 (affected, PyPI) 0.21.5 (affected, PyPI) 0.21.6 (affected, PyPI) 0.22.0 (affected, PyPI) 0.22.0a0 (affected, PyPI) 0.22.0b0 (affected, PyPI) 0.22.0b1 (affected, PyPI) 0.22.0b2 (affected, PyPI) 0.22.0b3 (affected, PyPI) 0.22.0b4 (affected, PyPI) 0.22.0b5 (affected, PyPI) 0.22.0b6 (affected, PyPI) 0.22.1 (affected, PyPI) 0.22.2 (affected, PyPI) 0.22.3 (affected, PyPI) 0.22.4 (affected, PyPI) 0.22.5 (affected, PyPI) 0.3 (affected, PyPI) 0.4 (affected, PyPI) 0.4.1 (affected, PyPI) 0.4.2 (affected, PyPI) 0.4.3 (affected, PyPI) 0.4.4 (affected, PyPI) 0.5.0 (affected, PyPI) 0.6.0 (affected, PyPI) 0.6.1 (affected, PyPI) 0.6.2 (affected, PyPI) 0.6.3 (affected, PyPI) 0.6.4 (affected, PyPI) 0.6.5 (affected, PyPI) 0.7.0 (affected, PyPI) 0.7.1 (affected, PyPI) 0.7.2 (affected, PyPI) 0.7.3 (affected, PyPI) 0.8.0 (affected, PyPI) 0.8.1 (affected, PyPI) 0.8.2 (affected, PyPI) 0.8.3 (affected, PyPI) 0.8.4 (affected, PyPI) 0.9.0 (affected, PyPI) 0.9.1 (affected, PyPI) 0.9.2 (affected, PyPI) 0.9.3 (affected, PyPI) 1.0.0 (affected, PyPI) 1.0.1 (affected, PyPI) 1.0.2 (affected, PyPI) 1.0.3 (affected, PyPI) 1.0.5 (affected, PyPI) 1.1.0 (affected, PyPI) 1.1.1 (affected, PyPI) 1.1.2 (affected, PyPI) 1.1.3 (affected, PyPI) 1.1.4 (affected, PyPI) 1.1.5 (affected, PyPI) 1.1.6 (affected, PyPI) 1.2.0 (affected, PyPI) 1.3.0 (affected, PyPI) 1.3.1 (affected, PyPI) 1.3.2 (affected, PyPI) 1.3.3 (affected, PyPI) 1.3.4 (affected, PyPI) 1.3.5 (affected, PyPI) 2.0.0 (affected, PyPI) 2.0.0rc1 (affected, PyPI) 2.0.1 (affected, PyPI) 2.0.2 (affected, PyPI) 2.0.3 (affected, PyPI) 2.0.4 (affected, PyPI) 2.0.5 (affected, PyPI) 2.0.6 (affected, PyPI) 2.0.7 (affected, PyPI) 2.1.0 (affected, PyPI) 2.2.0 (affected, PyPI) 2.2.1 (affected, PyPI) 2.2.2 (affected, PyPI) 2.2.3 (affected, PyPI) 2.2.4 (affected, PyPI) 2.2.5 (affected, PyPI) 2.3.0 (affected, PyPI) 2.3.0a1 (affected, PyPI) 2.3.0a2 (affected, PyPI) 2.3.0a3 (affected, PyPI) 2.3.0a4 (affected, PyPI) 2.3.1 (affected, PyPI) 2.3.10 (affected, PyPI) 2.3.1a1 (affected, PyPI) 2.3.2 (affected, PyPI) 2.3.2b2 (affected, PyPI) 2.3.2b3 (affected, PyPI) 2.3.3 (affected, PyPI) 2.3.4 (affected, PyPI) 2.3.5 (affected, PyPI) 2.3.6 (affected, PyPI) 2.3.7 (affected, PyPI) 2.3.8 (affected, PyPI) 2.3.9 (affected, PyPI) 3.0.0 (affected, PyPI) 3.0.0b0 (affected, PyPI) 3.0.0b1 (affected, PyPI) 3.0.0b2 (affected, PyPI) 3.0.0b3 (affected, PyPI) 3.0.0b4 (affected, PyPI) 3.0.1 (affected, PyPI) 3.0.2 (affected, PyPI) 3.0.3 (affected, PyPI) 3.0.4 (affected, PyPI) 3.0.5 (affected, PyPI) 3.0.6 (affected, PyPI) 3.0.7 (affected, PyPI) 3.0.8 (affected, PyPI) 3.0.9 (affected, PyPI) 3.1.0 (affected, PyPI) 3.1.1 (affected, PyPI) 3.1.2 (affected, PyPI) 3.1.3 (affected, PyPI) 3.10.0 (affected, PyPI) 3.10.0b1 (affected, PyPI) 3.10.0rc0 (affected, PyPI) 3.10.1 (affected, PyPI) 3.10.10 (affected, PyPI) 3.10.11 (affected, PyPI) 3.10.11rc0 (affected, PyPI) 3.10.2 (affected, PyPI) 3.10.3 (affected, PyPI) 3.10.4 (affected, PyPI) 3.10.5 (affected, PyPI) 3.10.6 (affected, PyPI) 3.10.6rc0 (affected, PyPI) 3.10.6rc1 (affected, PyPI) 3.10.6rc2 (affected, PyPI) 3.10.7 (affected, PyPI) 3.10.8 (affected, PyPI) 3.10.9 (affected, PyPI) 3.11.0 (affected, PyPI) 3.11.0b0 (affected, PyPI) 3.11.0b1 (affected, PyPI) 3.11.0b2 (affected, PyPI) 3.11.0b3 (affected, PyPI) 3.11.0b4 (affected, PyPI) 3.11.0b5 (affected, PyPI) 3.11.0rc0 (affected, PyPI) 3.11.0rc1 (affected, PyPI) 3.11.0rc2 (affected, PyPI) 3.11.1 (affected, PyPI) 3.11.10 (affected, PyPI) 3.11.11 (affected, PyPI) 3.11.12 (affected, PyPI) 3.11.13 (affected, PyPI) 3.11.14 (affected, PyPI) 3.11.15 (affected, PyPI) 3.11.16 (affected, PyPI) 3.11.17 (affected, PyPI) 3.11.18 (affected, PyPI) 3.11.2 (affected, PyPI) 3.11.3 (affected, PyPI) 3.11.4 (affected, PyPI) 3.11.5 (affected, PyPI) 3.11.6 (affected, PyPI) 3.11.7 (affected, PyPI) 3.11.8 (affected, PyPI) 3.11.9 (affected, PyPI) 3.12.0 (affected, PyPI) 3.12.0b0 (affected, PyPI) 3.12.0b1 (affected, PyPI) 3.12.0b2 (affected, PyPI) 3.12.0b3 (affected, PyPI) 3.12.0rc0 (affected, PyPI) 3.12.0rc1 (affected, PyPI) 3.12.1 (affected, PyPI) 3.12.10 (affected, PyPI) 3.12.11 (affected, PyPI) 3.12.12 (affected, PyPI) 3.12.13 (affected, PyPI) 3.12.14 (affected, PyPI) 3.12.15 (affected, PyPI) 3.12.1rc0 (affected, PyPI) 3.12.2 (affected, PyPI) 3.12.3 (affected, PyPI) 3.12.4 (affected, PyPI) 3.12.6 (affected, PyPI) 3.12.7 (affected, PyPI) 3.12.7rc0 (affected, PyPI) 3.12.8 (affected, PyPI) 3.12.9 (affected, PyPI) 3.13.0 (affected, PyPI) 3.13.1 (affected, PyPI) 3.13.2 (affected, PyPI) 3.13.3 (affected, PyPI) 3.13.4 (affected, PyPI) 3.13.5 (affected, PyPI) 3.14.0 (affected, PyPI) 3.14.1 (affected, PyPI) 3.14.2 (affected, PyPI) 3.14.3 (affected, PyPI) 3.2.0 (affected, PyPI) 3.2.1 (affected, PyPI) 3.3.0 (affected, PyPI) 3.3.0a0 (affected, PyPI) 3.3.1 (affected, PyPI) 3.3.2 (affected, PyPI) 3.3.2a0 (affected, PyPI) 3.4.0 (affected, PyPI) 3.4.0a0 (affected, PyPI) 3.4.0a3 (affected, PyPI) 3.4.0b1 (affected, PyPI) 3.4.0b2 (affected, PyPI) 3.4.1 (affected, PyPI) 3.4.2 (affected, PyPI) 3.4.3 (affected, PyPI) 3.4.4 (affected, PyPI) 3.5.0 (affected, PyPI) 3.5.0a1 (affected, PyPI) 3.5.0b1 (affected, PyPI) 3.5.0b2 (affected, PyPI) 3.5.0b3 (affected, PyPI) 3.5.1 (affected, PyPI) 3.5.2 (affected, PyPI) 3.5.3 (affected, PyPI) 3.5.4 (affected, PyPI) 3.6.0 (affected, PyPI) 3.6.0a0 (affected, PyPI) 3.6.0a1 (affected, PyPI) 3.6.0a11 (affected, PyPI) 3.6.0a12 (affected, PyPI) 3.6.0a2 (affected, PyPI) 3.6.0a3 (affected, PyPI) 3.6.0a4 (affected, PyPI) 3.6.0a5 (affected, PyPI) 3.6.0a6 (affected, PyPI) 3.6.0a7 (affected, PyPI) 3.6.0a8 (affected, PyPI) 3.6.0a9 (affected, PyPI) 3.6.0b0 (affected, PyPI) 3.6.1 (affected, PyPI) 3.6.1b3 (affected, PyPI) 3.6.1b4 (affected, PyPI) 3.6.2 (affected, PyPI) 3.6.2a0 (affected, PyPI) 3.6.2a1 (affected, PyPI) 3.6.2a2 (affected, PyPI) 3.6.3 (affected, PyPI) 3.7.0 (affected, PyPI) 3.7.0b0 (affected, PyPI) 3.7.0b1 (affected, PyPI) 3.7.1 (affected, PyPI) 3.7.2 (affected, PyPI) 3.7.3 (affected, PyPI) 3.7.4 (affected, PyPI) 3.7.4.post0 (affected, PyPI) 3.8.0 (affected, PyPI) 3.8.0a7 (affected, PyPI) 3.8.0b0 (affected, PyPI) 3.8.1 (affected, PyPI) 3.8.2 (affected, PyPI) 3.8.3 (affected, PyPI) 3.8.4 (affected, PyPI) 3.8.5 (affected, PyPI) 3.8.6 (affected, PyPI) 3.9.0 (affected, PyPI) 3.9.0b0 (affected, PyPI) 3.9.0b1 (affected, PyPI) 3.9.0rc0 (affected, PyPI) 3.9.1 (affected, PyPI) 3.9.2 (affected, PyPI) 3.9.3 (affected, PyPI) 3.9.4 (affected, PyPI) 3.9.4rc0 (affected, PyPI) 3.9.5 (affected, PyPI) Ecosystem version events: introduced 0; fixed 3.14.4 Source events (ECOSYSTEM) `[ { "introduced": "0" }, { "fixed": "3.14.4" } ]` Other versions: unaffected	OSV GHSA-2g87-pp6c-29x5

Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.

CVSS assessments

CVSS scores, vectors and reporting authorities
Version / score	Vector	Authority
4.0 / 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`	CNA: GitHub_M

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-2g87-pp6c-29x5CNA: GitHub_M · x_refsource_CONFIRM
https://github.com/aio-libs/aiohttp/pull/13352CNA: GitHub_M · x_refsource_MISC
https://github.com/aio-libs/aiohttp/pull/13612CNA: GitHub_M · x_refsource_MISC
https://github.com/aio-libs/aiohttp/commit/09bcaa73ff084a0c539bbf16a0a78743acb7141fCNA: GitHub_M · x_refsource_MISC
https://github.com/aio-libs/aiohttp/commit/6a4f6682817839313b04b8e5cea2b39c1a88ab4fCNA: GitHub_M · x_refsource_MISC
https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4CNA: GitHub_M · x_refsource_MISC
https://github.com/advisories/GHSA-2g87-pp6c-29x5OSV / GitHub Security Advisories · advisory
https://osv.dev/vulnerability/GHSA-2g87-pp6c-29x5OSV / GitHub Security Advisories · osv

For agents and automation

Read public disclosures for free as Markdown or JSON. Compatible browsers also expose native WebMCP tools to search disclosures, read this page, and discover API access.

Use the ontology-linked Cyber API with x402 pay per request, or a Y2 Pro or Elite API key with the intel:cyber scope.

Get an API key Use x402 Connect an agent

Endpoints and access details

https://api.y2.dev/api/v2/cyber/cves
https://api.y2.dev/api/v2/cyber/cves/{cveId}

A workspace owner or admin can create a Pro or Elite API key. Send Authorization: Bearer <Y2_API_KEY> from your trusted agent runtime.

For x402, omit Authorization and read the HTTP 402 payment challenge before signing a retry. Public browser tools do not make payments.

Agent access JSON · OpenAPI · CVE API guide