CVE-2026-128129

CVSS 8.2 (high) · published 2026-11-13

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.

Weakness: CWE-770

Source: NVD CVE-2026-128129

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

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