Python Library aiohttp < 3.14.0 Header Injection

medium Nessus Plugin ID 324957

Synopsis

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

Description

The version of the aiohttp Python library installed on the remote host is prior to 3.14.0. It is, therefore, affected by a vulnerability:

- Prior to 3.14.0, attacker-controlled input included into multipart/payload headers can be used to modify a request to inject additional headers or similar. In the unlikely situation that an application is passing user-controlled strings into MultipartWriter.append(headers=...) or Payload.headers, then an attacker may be able to modify the request to inject headers or change the contents of the request. (CVE-2026-50269)

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

Solution

Upgrade to aiohttp version 3.14.0 or later.

See Also

http://www.nessus.org/u?a7a0488e

Plugin Details

Severity: Medium

ID: 324957

File Name: python_aiohttp_3_14_0.nasl

Version: 1.2

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 7/3/2026

Updated: 7/6/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.95

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-50269

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: Medium

Base Score: 6.9

Threat Score: 2.7

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/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

Exploit Ease: No known exploits are available

Patch Publication Date: 6/15/2026

Vulnerability Publication Date: 6/15/2026

Reference Information

CVE: CVE-2026-50269

IAVA: 2026-A-0636