---
schema_version: '1.0'
id: security-20260714-b423cc
url: https://osv.dev/vulnerability/PYSEC-2026-2099
url_hash: b423cc3a4b8c69479da0d25c4d320a18cd42023826a5c1865e962e36ed7bce5d
canonical_url: https://osv.dev/vulnerability/PYSEC-2026-2099
source: osv:pypa
category: security/library
category_raw: cve/library
region: null
tags:
- cve
- CVE-2026-34517
- PYSEC-2026-2099
- severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- aiohttp
- PyPI
lang: en
published_at: '2026-04-01T21:16:59Z'
fetched_at: '2026-07-14T06:42:23Z'
updated_at: '2026-07-14T06:42:55Z'
status: published
content_hash: 77d7a9eeb39efc6acf6c6e0f8fcbb05f941afe5429da2ab60d04172cbc4a20b5
license_note: full
summary: 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.
summary_source: rss
summary_en: 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.
entities: []
key_facts: []
related: []
related_auto: []
title: CVE-2026-34517 — aiohttp
---

# CVE-2026-34517 — aiohttp

## TL;DR
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.

## Key Points
- cve / CVE-2026-34517 / PYSEC-2026-2099 / severity:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L / aiohttp / PyPI

## Details
**Severity:** CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
**Advisory:** PYSEC-2026-2099 (CVE-2026-34517)

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

**Details:**
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.

**References:**
- https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4
- https://github.com/aio-libs/aiohttp/commit/cbb774f38330563422ca0c413a71021d7b944145
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3wq7-rqq7-wx6j

_Data: OSV.dev (upstream: pypa) — https://osv.dev/vulnerability/PYSEC-2026-2099_

## Source
元記事: [CVE-2026-34517 — aiohttp](https://osv.dev/vulnerability/PYSEC-2026-2099) — published 2026-04-01T21:16:59Z