CVE-2026-128129: DoS

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, aiohttp buffers all additional connection data received while a request marked for upgrade, such as a WebSocket handshake, is being handled, without a size limit or flow control. A remote attacker can stream data behind an upgrade request to a handler that does not immediately accept or reject the upgrade and cause unbounded memory consumption. This issue is fixed in version 3.14.4.

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Weakness Type (CWE)

CWE-770 CWE-770

References

Other References

https://github.com/aio-libs/aiohttp/commit/3d850ee9b92573c7e913821cbcb96005beb3f4df https://github.com/aio-libs/aiohttp/commit/c207cadb257e0959b192ffca0548eca8c71eb96a https://github.com/aio-libs/aiohttp/pull/13501 https://github.com/aio-libs/aiohttp/pull/13511 https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4 https://github.com/aio-libs/aiohttp/security/advisories/GHSA-pw86-h8fm-j323

Frequently Asked Questions

What is CVE-2026-128129? +

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, aiohttp buffers all additional connection data received while a request marked for upgrade, such as a WebSocket handshake, is being handled, without a size limit or flow control. A remote attacker can stream data behind an upgrade request to a handler that does not immediately accept or reject the upgrade and cause unbounded memory consumption. This issue is fixed in version 3.14.4.

How do I check if I'm vulnerable to CVE-2026-128129? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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