AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, the C WebSocket reader adds a declared frame length to the size of an already buffered partial message using signed 64-bit arithmetic. A length near two to the power of 63 can overflow, allowing the max_msg_size check to pass.
A remote peer can send a small non-final fragment followed by an oversized message and cause unbounded memory consumption. The Python WebSocket reader is unaffected. This issue is fixed in version 3.14.4.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v3.1
Weakness Type (CWE)
References 6
https://github.com/aio-libs/aiohttp/commit/8c8906a19f64e52ef6a7d44d65217eb3c5af…
security-advisories@github.com
https://github.com/aio-libs/aiohttp/commit/8cfbe9abe5e11b84006a10f9bdf82bf60767…
security-advisories@github.com
https://github.com/aio-libs/aiohttp/pull/13415
security-advisories@github.com
https://github.com/aio-libs/aiohttp/pull/13494
security-advisories@github.com
https://github.com/aio-libs/aiohttp/releases/tag/v3.14.4
security-advisories@github.com
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-3rp8-rxj8-mvjw
security-advisories@github.com