CVE-2026-69243 MEDIUM

CVE-2026-69243: AIOHTTP: HTTP request smuggling via WebSocket upgrade

Vendor Aio-Libs
Product aiohttp
Weakness CWE-444
Published August 3, 2026
Last update August 5, 2026

CVSS base score

6.3/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the HTTP parsers were vulnerable to a request smuggling attack relating to WebSocket upgrades. If using the server-side component, an attacker may be able to execute a request smuggling vulnerability using an edge case in the WebSocket upgrade procedure. A WebSocket upgrade request with a body could cause the parser to switch protocols before the complete request body was received, leaving trailing bytes to be handled as upgraded-protocol or pipelined data rather than normal HTTP body data. This issue is fixed in version 3.14.2.

Key dates

02Disclosure timeline

August 3, 2026 CVE published
August 5, 2026 Record updated