---
id: CVE-2025-69229
aliases:
  - GHSA-g84x-mcqj-x9qq
  - PYSEC-2026-1106
title: AIOHTTP vulnerable to DoS through chunked messages
summary: AIOHTTP vulnerable to DoS through chunked messages
severity: medium
vendor: aiohttp
product: aiohttp
ecosystem: pip
affected:
  - aiohttp < 3.13.3
patched:
  - aiohttp 3.13.3
published: '2026-01-05'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:33.073865205Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-g84x-mcqj-x9qq'
references:
  - url: >-
      https://github.com/aio-libs/aiohttp/security/advisories/GHSA-g84x-mcqj-x9qq
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-69229'
  - url: >-
      https://github.com/aio-libs/aiohttp/commit/4ed97a4e46eaf61bd0f05063245f613469700229
  - url: >-
      https://github.com/aio-libs/aiohttp/commit/dc3170b56904bdf814228fae70a5501a42a6c712
  - url: 'https://github.com/aio-libs/aiohttp'
tags:
  - osv
  - pip
epss: 0.00395
epssPercentile: 0.33579
ingestedAt: '2026-07-08T18:25:49.671Z'
---

## Overview

### Summary

Handling of chunked messages can result in excessive blocking CPU usage when receiving a large number of chunks.

### Impact

If an application makes use of the `request.read()` method in an endpoint, it may be possible for an attacker to cause the server to spend a moderate amount of blocking CPU time (e.g. 1 second) while processing the request. This could potentially lead to DoS as the server would be unable to handle other requests during that time.

-----

Patch: https://github.com/aio-libs/aiohttp/commit/dc3170b56904bdf814228fae70a5501a42a6c712
Patch: https://github.com/aio-libs/aiohttp/commit/4ed97a4e46eaf61bd0f05063245f613469700229

## Affected packages

- `aiohttp < 3.13.3`

## Remediation

Upgrade to a patched release:

- `aiohttp 3.13.3`