Information Disclosure in AIOHTTP Static Resource Handler on Windows

Publication date: 2026-04-01

Last updated on: 2026-04-15

Assigner: GitHub, Inc.

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, on Windows the static resource handler may expose information about a NTLMv2 remote path. This issue has been patched in version 3.13.4.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-04-01

Last Modified

2026-04-15

Generated

2026-07-06

AI Q&A

2026-04-02

EPSS Evaluated

2026-07-05

NVD

CVE-2026-34515

Affected Vendors & Products

Vendor	Product	Version / Range
aiohttp	aiohttp	to 3.13.4 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-918	The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
CWE-36	The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as "/abs/path" that can resolve to a location that is outside of that directory.

Attack-Flow Graph

Executive Summary

This vulnerability exists in AIOHTTP, an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, on Windows systems, the static resource handler could expose information about a NTLMv2 remote path. This exposure could potentially leak sensitive information related to network authentication paths.

Impact Analysis

The vulnerability may lead to unintended disclosure of NTLMv2 remote path information on Windows systems using affected versions of AIOHTTP. This information exposure could be leveraged by attackers to gain insights into network authentication details, potentially aiding in further attacks or reconnaissance.

Mitigation Strategies

To mitigate this vulnerability, you should upgrade AIOHTTP to version 3.13.4 or later, as this version contains the patch that fixes the issue with the static resource handler exposing NTLMv2 remote path information on Windows.

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