Inconsistent interpretation of HTTP requests in aiohttp - CVE-2026-69243

Vulnerability identifier: #VU139888

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-69243

CWE-ID: CWE-444

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform HTTP request smuggling attacks.

The vulnerability exists due to improper validation of HTTP requests within WebSocket upgrade. A remote attacker can send a specially crafted HTTP request to the server and smuggle arbitrary HTTP headers.

Successful exploitation of vulnerability may allow an attacker to poison HTTP cache and perform phishing attacks.

aiohttp
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Desktop 15
SUSE Manager Server
SUSE Manager Retail Branch Server
SUSE Manager Proxy
Public Cloud Module
Python 3 Module
openSUSE Leap
openEuler
Fedora
python311-aiohttp-debuginfo
python-aiohttp-debugsource
python311-aiohttp
python-aiohttp-help
python3-aiohttp
python-aiohttp-debuginfo
python-aiohttp

Install updates from vendor's website.

aiohttp - update to 3.14.2
python311-aiohttp-debuginfo - update to 3.9.3-150400.10.46.1
python-aiohttp-debugsource - update to 3.9.3-150400.10.46.1
python311-aiohttp - update to 3.9.3-150400.10.46.1
python-aiohttp-help - update to 3.14.3-1
python3-aiohttp - update to 3.14.3-1
python-aiohttp-debugsource - update to 3.14.3-1
python-aiohttp-debuginfo - update to 3.14.3-1
python-aiohttp - update to 3.14.3-1
python-aiohttp - addressed in versions 3.14.3-3.fc45, 3.14.3-3.fc46

• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mfx4-hv73-q22v

• Multiple vulnerabilities in aiohttp
• Fedora 46 update for python-aiohttp
• Fedora 45 update for python-aiohttp
• openEuler 24.03 LTS SP1 update for python-aiohttp
• openEuler 24.03 LTS SP4 update for python-aiohttp
• openEuler 24.03 LTS SP3 update for python-aiohttp
• SUSE update for python-aiohttp