CVE-2026-34516AIOHTTP: Multipart Header Size Bypass

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, a response with an excessive number of multipart headers may be allowed to use more memory than intended, potentially allowing a DoS vulnerability. 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-m5qp-6w8w-w647 PatchVendor Advisory
• https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6f Patch
• https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4 Release Notes