---
schema_version: '1.0'
id: security-20260711-d6808c
url: https://osv.dev/vulnerability/GHSA-3wq7-rqq7-wx6j
url_hash: d6808c0a405ac41b4fdf7d6ce8f479ef30a3434ca79ec1501b7a6d8261457be9
canonical_url: https://osv.dev/vulnerability/GHSA-3wq7-rqq7-wx6j
source: osv:ghsa
category: security/library
category_raw: cve/library
region: null
tags:
- cve
- CVE-2026-34517
- GHSA-3wq7-rqq7-wx6j
- severity: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
- aiohttp
- PyPI
lang: en
published_at: '2026-04-01T21:47:07Z'
fetched_at: '2026-07-11T06:37:17Z'
updated_at: '2026-07-11T06:37:45Z'
status: published
content_hash: cbf163d92d2406943217d73b7c11047d899913ca136a7e1b771e90017f26190b
license_note: full
summary: AIOHTTP has late size enforcement for non-file multipart fields causes memory
  DoS
summary_source: rss
summary_en: AIOHTTP has late size enforcement for non-file multipart fields causes
  memory DoS
entities:
- name: HashTag
  type: concept
- name: latecapitalism
  type: organization
- name: hypothesizes, suggests
  type: agent_openclaw
key_facts: []
related: []
related_auto:
- name: SustainableQuantumComputing
  type: concept
  weight: 3.0
- name: agent_openclaw
  type: person
  weight: 1.0
title: 'CVE-2026-34517: AIOHTTP has late size enforcement for non-file multipart fields
  causes memory DoS'
---

# CVE-2026-34517: AIOHTTP has late size enforcement for non-file multipart fields causes memory DoS

## TL;DR
AIOHTTP has late size enforcement for non-file multipart fields causes memory DoS

## Key Points
- cve / CVE-2026-34517 / GHSA-3wq7-rqq7-wx6j / severity: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 / aiohttp / PyPI

## Details
**Severity:** 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
**Advisory:** GHSA-3wq7-rqq7-wx6j (CVE-2026-34517)

**Affected (your watchlist):**
- `PyPI:aiohttp` 3.13.3 → fixed in 3.13.4 [docker/docker-strands]

**Details:**
### 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

**References:**
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3wq7-rqq7-wx6j
- https://nvd.nist.gov/vuln/detail/CVE-2026-34517
- https://github.com/aio-libs/aiohttp/commit/cbb774f38330563422ca0c413a71021d7b944145
- https://github.com/aio-libs/aiohttp
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4

_Data: OSV.dev (upstream: ghsa) — https://osv.dev/vulnerability/GHSA-3wq7-rqq7-wx6j_

## Source
元記事: [CVE-2026-34517: AIOHTTP has late size enforcement for non-file multipart fields causes memory DoS](https://osv.dev/vulnerability/GHSA-3wq7-rqq7-wx6j) — published 2026-04-01T21:47:07Z