CVE-2026-34513AIOHTTP: Denial of Service (DoS) via Unbounded DNS Cache in TCPConnector

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.

Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.

Affected products and versions

References and patches

• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-hcc4-c3v8-rx92 PatchVendor Advisory
• https://github.com/aio-libs/aiohttp/commit/c4d77c3533122be353b8afca8e8675e3b4cbda98 Patch
• https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 Release Notes