CVE-2026-59881
AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-20 |
| Vendor | aio-libs |
| Product | aiohttp |
| Published | Jul 30, 2026 |
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Affected Versions
aio-libs / aiohttp
< 3.14.2
References
github.com: https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7 github.com: https://github.com/aio-libs/aiohttp/pull/12978 github.com: https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6 github.com: http://github.com/aio-libs/aiohttp/releases/tag/v3.14.2