Inconsistent interpretation of HTTP requests in aiohttp - #VU153861
Published: October 7, 2026
Vulnerability identifier: #VU153861
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to smuggle HTTP requests.
The vulnerability exists due to improper HTTP request parsing in the aiohttp pure-Python parser when processing HTTP requests. A remote attacker can send crafted HTTP requests to smuggle HTTP requests.
Exposure requires use of the Python parser, including configurations using AIOHTTP_NO_EXTENSIONS or installations without a standard wheel.
Affected software
aiohttp
Remediation
Install security update from vendor's website.
aiohttp - update to 3.14.4