CVE-2026-63495

Name	CVE-2026-63495
Description	Libevent is an event notification library. From 2.2.0-alpha-dev until 2.2.2-alpha, the libevent WebSocket server in ws.c accumulates fragmented frames in evws->incomplete_frames without enforcing a total message-size limit. An unauthenticated remote client can repeatedly send fragmented WebSocket frames below WS_MAX_RECV_FRAME_SZ with FIN=0, causing the evbuffer to grow without bound until the process or host exhausts memory. This issue is fixed in version 2.2.2-alpha.
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)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
libevent (PTS)	bullseye	2.1.12-stable-1	fixed
	bookworm	2.1.12-stable-8	fixed
	trixie	2.1.12-stable-10	fixed
	forky, sid	2.1.13-stable-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
libevent	source	(unstable)	(not affected)

Notes

- libevent <not-affected> (Vulnerable code not present)
https://github.com/libevent/libevent/security/advisories/GHSA-qx89-wf2v-vgmx
Fixed by: https://github.com/libevent/libevent/commit/291c4d1cd75695e898030ebd5c4ddf26c094077b (release-2.2.2-alpha)