AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, for some multipart form fields, aiohttp read the entire field into memory before checking client_max_size. This issue has been patched in version 3.13.4.
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3wq7-rqq7-wx6j
https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
https://github.com/aio-libs/aiohttp/commit/cbb774f38330563422ca0c413a71021d7b944145
Published: 2026-04-01
Updated: 2026-04-03
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 6.9
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
Severity: Medium
EPSS: 0.0004