Input validation error in aiohttp - CVE-2026-54274

Vulnerability identifier: #VU133989

CSH Severity: Medium

CVSS v4: 8.7 [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]

CVE-ID: CVE-2026-54274

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper input validation in websocket frame payload handling when processing large incomplete websocket frame payloads. A remote attacker can send large incomplete websocket frame payloads to cause a denial of service.

The issue can bypass the usual size limits on memory use.

aiohttp
SUSE Linux Enterprise Server 15 SP6
SUSE Linux Enterprise Server 15 SP5
SUSE Linux Enterprise Server 15 SP4
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Linux Enterprise High Performance Computing ESPOS 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Desktop 15
SUSE Manager Server
SUSE Manager Proxy
SUSE Manager Retail Branch Server
Public Cloud Module
Python 3 Module
openSUSE Leap
openEuler
python-aiohttp-debugsource
python3-aiohttp-debuginfo
python3-aiohttp
python311-aiohttp
python311-aiohttp-debuginfo
python-aiohttp
python-aiohttp-debuginfo
python-aiohttp-help

Install security update from vendor's website.

aiohttp - update to 3.14.1
python-aiohttp-debugsource - addressed in versions 3.6.0-150100.3.38.1, 3.9.3-150400.10.43.1
python3-aiohttp-debuginfo - update to 3.6.0-150100.3.38.1
python3-aiohttp - update to 3.6.0-150100.3.38.1
python311-aiohttp - update to 3.9.3-150400.10.43.1
python311-aiohttp-debuginfo - update to 3.9.3-150400.10.43.1
python-aiohttp - update to 3.14.1-1
python-aiohttp-debuginfo - update to 3.14.1-1
python-aiohttp-debugsource - update to 3.14.1-1
python-aiohttp-help - update to 3.14.1-1
python3-aiohttp - update to 3.14.1-1

• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-xcgm-r5h9-7989
• https://github.com/aio-libs/aiohttp/commit/14b6ee851fb16ec199acb950de0c82d476799e7d

• Multiple vulnerabilities in aiohttp
• openEuler 24.03 LTS SP1 update for python-aiohttp
• openEuler 24.03 LTS SP3 update for python-aiohttp
• SUSE update for python-aiohttp
• SUSE update for python-aiohttp