CVE-2025-69229: PYSEC-2026-1106 - AIOHTTP vulnerable to DoS through chunked messages

CVE-2025-69229 · Severity: medium · CVSS 5.3 · Published 2026-01-06

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. In versions 3.13.2 and below, handling of chunked messages can result in excessive blocking CPU usage when receiving a large number of chunks. 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. This issue is fixed in version 3.13.3.

Technologies: Aiohttp, aiohttp (PyPI). Vendors: Aiohttp, PyPI.

Quick answers

Is CVE-2025-69229 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2025-69229 being exploited in the wild.
How severe is CVE-2025-69229?
Medium severity, with a CVSS score of 5.3, published 6 January 2026.
Which products and versions are affected?
aiohttp (PyPI) ECOSYSTEM:introduced=0,fixed=3.13.3.
Is there a fix for CVE-2025-69229?
Yes. aiohttp (PyPI): upgrade to 3.13.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2025-69229?
Check whether you run Aiohttp or aiohttp (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • aiohttp (PyPI): upgrade to 3.13.3 or later
    pip install "aiohttp>=3.13.3"

Affected products

  • Aiohttp
  • aiohttp (PyPI) ECOSYSTEM:introduced=0,fixed=3.13.3

Identifiers

  • CVE-2025-69229
  • GHSA-g84x-mcqj-x9qq
  • PYSEC-2026-1106

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.