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.

CVSS 4.0

6.3CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 38% of CVEs (scores of 2026-10-25)

CWE

CWE-444

Published

2026-08-03

Modified

2026-10-23

Record from

the NVD, synced 2026-10-24

Packages (OSV)

References

• 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

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