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aiohttp < 3.14.2 HTTP Request Smuggling

medium Nessus Plugin ID 333342

Synopsis

A Python library installed on the remote host is affected by a request smuggling vulnerability.

Description

The version of aiohttp installed on the remote host is prior to 3.14.2. It is, therefore, affected by a request smuggling vulnerability:

 - 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. (CVE-2026-69243)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade to aiohttp version 3.14.2 or later.

See Also

http://www.nessus.org/u?99a78546

Plugin Details

Severity: Medium

ID: 333342

File Name: aiohttp_3_14_2.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 8/7/2026

Updated: 8/7/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.4

CVSS v2

Risk Factor: High

Base Score: 8.5

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

CVSS Score Source: CVE-2026-69243

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v4

Risk Factor: Medium

Base Score: 6.3

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

Vulnerability Information

CPE: cpe:/a:aiohttp:aiohttp

Patch Publication Date: 8/3/2026

Vulnerability Publication Date: 8/3/2026

Reference Information

CVE: CVE-2026-69243

IAVA: 2026-A-0818