CVE-2025-69229 MEDIUM

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

Vendor Aio-Libs
Product aiohttp
Weakness CWE-770 · Uncontrolled resource consumption
Published January 5, 2026
Last update January 6, 2026

CVSS base score

6.6/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

January 5, 2026 CVE published
January 6, 2026 Record updated