CVE-2026-59881
AIOHTTP: WebSocket client accepts compressed frames without negotiated permessage-deflate
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.
No summary for this CVE yet.
Weaknesses
Affected Products
aio-libs
oss-projectaka aiosmtpd, aiohttp, aiohttp session
Exploitability
No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.
Attack Graph
Products CVE Techniques Tactics
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MITRE ATT&CK
1 technique Initial Access
References
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
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