Vulnerability Report

CVE-2026-69243

Title: AIOHTTP Server Request Smuggling via WebSocket Upgrade

Other

Proof Of Concept

PoC Available for CVE-2026-69243

CWE Category CWE-444
Published Date Aug 03, 2026
Modified Date Aug 05, 2026
Exploit Status Available
Score 6.3 CVSS v4.0
Exploit Probability (EPSS)
0.27%

Vulnerability Summary

CVE-2026-69243: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the HTTP parsers were vulnerable to a request smuggling attack relating to WebSocket upgrades. If using the server-side component, an attacker may be able to execute a request smuggling vulnerability using an edge case in the WebSocket upgrade procedure. A WebSocket upgrade request with a body could cause the parser to switch protocols before the complete request body was received, leaving trailing bytes to be handled as upgraded-protocol or pipelined data rather than normal HTTP body data. This issue is fixed in version 3.14.2.

Impacted Vendors

Analysis in Progress...

Reference Links

https://github.com/aio-libs/aiohttp/commit/6ae358f0983c3f4d6f67692b2f8e65dc8e091c98 https://github.com/aio-libs/aiohttp/pull/13017 https://github.com/aio-libs/aiohttp/releases/tag/v3.14.2 https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mfx4-hv73-q22v
CVSS v4.0
Source Entity [email protected]
Severity MEDIUM
6.3
Attack Vector
NETWORK
Complexity
HIGH
Privileges
N/A
Interaction
NONE
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
N/A
RAW VECTOR CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-69243 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/JVBotelho/cve-2026-69243-poc-aiohttp-smuggling
View Code
MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity HIGH
Privileges N/A
Interaction NONE
CVSS Vector String CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected Stack

No specific products linked.