CVE-2026-59881

Name	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.
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	1143160

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
python-aiohttp (PTS)	bullseye	3.7.4-1	vulnerable
	bullseye (security)	3.7.4-1+deb11u2	vulnerable
	bookworm, bookworm (security)	3.8.4-1+deb12u1	vulnerable
	trixie (security), trixie	3.11.16-1+deb13u1	vulnerable
	forky, sid	3.14.1-4	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)			1143160

Notes

[trixie] - python-aiohttp <no-dsa> (Minor issue)
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mq44-7p77-q5h7
https://github.com/aio-libs/aiohttp/pull/12978
Fixed by: https://github.com/aio-libs/aiohttp/commit/47fb6ae354d4fa22048f4dbe7dbf82b625f0a2f6 (v3.14.2)