CVE-2026-128128

high

Description

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.

References

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3rp8-rxj8-mvjw

https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4

https://github.com/aio-libs/aiohttp/pull/13494

https://github.com/aio-libs/aiohttp/pull/13415

https://github.com/aio-libs/aiohttp/commit/8cfbe9abe5e11b84006a10f9bdf82bf607671dab

https://github.com/aio-libs/aiohttp/commit/8c8906a19f64e52ef6a7d44d65217eb3c5af413f

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-125760

Details

Source: Mitre, NVD

Published: 2026-11-13

Updated: 2026-11-13

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High