CVE-2026-128126AIOHTTP: Too many URL-encoded form fields block the event loop

Descripción

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Request.post() does not limit the number of fields in a URL-encoded form body, and inserting many repeated keys into MultiDict takes quadratic time on the event loop. A remote attacker can send a form POST within client_max_size to a handler that calls Request.post() and block the event loop. This issue is fixed in version 3.14.4.

Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.

Productos y versiones afectados

Referencias y parches

• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-xgw8-8ccx-rmqh
• https://github.com/aio-libs/aiohttp/pull/13738
• https://github.com/aio-libs/aiohttp/pull/13741
• https://github.com/aio-libs/aiohttp/commit/615fec3d4f088f30d2ee72cad760152e92aa1c53
• https://github.com/aio-libs/aiohttp/commit/8b0100572936df28977b9de8a6cc7e464c0b521e
• https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4