CVE-2025-11677

Name	CVE-2025-11677
Description	Use After Free in WebSocket server implementation in lws_handshake_server in warmcat libwebsockets may allow an attacker, in specific configurations where the user provides a callback function that handles LWS_CALLBACK_HTTP_CONFIRM_UPGRADE, to achieve denial of service.
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	1118747

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
libwebsockets (PTS)	bullseye	4.0.20-2	vulnerable
	bookworm	4.1.6-3	vulnerable
	trixie	4.3.5-1	vulnerable
	forky, sid	4.3.5-3	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
libwebsockets	source	(unstable)	4.3.5-3			1118747

Notes

[trixie] - libwebsockets <no-dsa> (Minor issue)
[bookworm] - libwebsockets <no-dsa> (Minor issue)
https://libwebsockets.org/git/libwebsockets/commit?id=2f082ec31261f556969160143ba94875d783971a