Skip to content
OpenAdvisories
High · 8.7 CVE-2026-128126 EUVD-2026-125758

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, Request.post() does not limit the number o…

Published Nov 13, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
aio-libs aiohttp < 3.14.4 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 python-aiohttp No fix yet —
Debian 13 python-aiohttp No fix yet —
Debian 12 python-aiohttp No fix yet —

References