CVE-2026-59881

Description

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.2, the WebSocket client accepts and decompresses frames with the RSV1 bit set even when the permessage-deflate extension was not negotiated, allowing a malicious server to cause unexpected CPU and memory consumption. This issue is fixed in version 3.14.2.

References

• http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2
• https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6
• https://github.com/aio-libs/aiohttp/pull/12978
• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7