Description
AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Versions 3.13.2 and below of the Python HTTP parser may allow a request smuggling attack with the presence of non-ASCII characters. If a pure Python version of AIOHTTP is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. This issue is fixed in version 3.13.3.
Scores
CVSS v3
6.5
EPSS
0.0004
EPSS Percentile
13.1%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-444
Status
published
Products (2)
aiohttp/aiohttp
< 3.13.3
pypi/aiohttp
0 - 3.13.3PyPI
Published
Jan 05, 2026
Tracked Since
Feb 18, 2026