CVE-2026-123817

Name	CVE-2026-123817
Description	AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, the WebSocket reader retains one bytes object for each transport read while reassembling an incomplete frame. A malicious peer can split a frame into many tiny reads so per-object overhead substantially exceeds the payload bytes allowed by max_msg_size. The condition affects a server receiving frames from a malicious client and a client receiving frames from a malicious server, and can cause excessive memory consumption or denial of service. This issue is fixed in version 3.14.4.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1153611

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-aiohttp (PTS)	bookworm	3.8.4-1+deb12u1	vulnerable
	bookworm (security)	3.8.4-1+deb12u2	vulnerable
	trixie (security), trixie	3.11.16-1+deb13u1	vulnerable
	forky, sid	3.14.3-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-aiohttp	source	(unstable)	(unfixed)			1153611

Notes

https://github.com/aio-libs/aiohttp/security/advisories/GHSA-2g87-pp6c-29x5
https://github.com/aio-libs/aiohttp/pull/13352
https://github.com/aio-libs/aiohttp/pull/13612
Fixed by: https://github.com/aio-libs/aiohttp/commit/09bcaa73ff084a0c539bbf16a0a78743acb7141f (v3.14.4)
Fixed by: https://github.com/aio-libs/aiohttp/commit/6a4f6682817839313b04b8e5cea2b39c1a88ab4f (v3.14.4)