CVE-2026-34513
Received Received - Intake
Unbounded DNS Cache in AIOHTTP Causes Memory DoS

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, an unbounded DNS cache could result in excessive memory usage possibly resulting in a DoS situation. This issue has been patched in version 3.13.4.
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Meta Information
Published
2026-04-01
Last Modified
2026-04-15
Generated
2026-06-16
AI Q&A
2026-04-02
EPSS Evaluated
2026-06-15
NVD
CVE-2026-34513
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
aiohttp aiohttp to 3.13.4 (exc)
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-770 The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
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Executive Summary

The vulnerability in AIOHTTP, an asynchronous HTTP client/server framework for asyncio and Python, involves an unbounded DNS cache prior to version 3.13.4. This means that the DNS cache could grow without limits, leading to excessive memory usage.

Such uncontrolled memory consumption could potentially cause a denial of service (DoS) situation by exhausting system resources.

This issue has been fixed in version 3.13.4 of AIOHTTP.

Impact Analysis

This vulnerability can impact you by causing excessive memory usage in applications using affected versions of AIOHTTP.

The unbounded DNS cache can lead to resource exhaustion, which may result in a denial of service (DoS) condition where the application or system becomes unresponsive or crashes.

Mitigation Strategies

To mitigate this vulnerability, you should upgrade AIOHTTP to version 3.13.4 or later, where the unbounded DNS cache issue has been patched.

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