GitHub Advisoryadvisory · PyPI

GHSA-3wq7-rqq7-wx6j AIOHTTP has late size enforcement for non-file multipart fields causes memory DoS

LOW Published 2026-04-01 Modified 2026-04-01 Official page ↗
Aliases
CVE-2026-34517
Ecosystem
PyPI
Packages
aiohttp
Severity
Low
CVSS 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/E:U
Weaknesses
CWE-770
Reviewed
2026-04-01

Affected packages

• PyPI aiohttp: < 3.13.4 → fixed in 3.13.4

Description

Summary For some multipart form fields, aiohttp read the entire field into memory before checking client_max_size. Impact If an application uses `Request.post()` an attacker can send a specially crafted multipart request to force significant temporary memory allocation even when the request is ultimately rejected. ----- Patch: https://github.com/aio-libs/aiohttp/commit/cbb774f38330563422ca0c413a71021d7b944145

Related

Alias · CVE (1)

  • CVE-2026-34517 AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. vulnerability

Weakness · CWE (1)

  • CWE-770 Allocation of Resources Without Limits or Throttling weakness

References