CVE-2026-123612

Name	CVE-2026-123612
Description	rustls 0.23.44 and 0.23.45 contain an information disclosure vulnerability that sends application data buffered before the handshake completes to the client-facing server when Encrypted Client Hello is rejected. Because start_traffic() queues plaintext from ClientConnection::writer() before sending the ech_required alert, the authenticated public_name server receives data intended for the inner server.
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	1151104

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
rust-rustls (PTS)	bookworm	0.20.8-4	vulnerable
	trixie	0.23.26+ds-1	vulnerable
	forky	0.23.45+ds-1	vulnerable
	sid	0.23.46+ds-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
rust-rustls	source	(unstable)	0.23.46+ds-1			1151104

https://rustsec.org/advisories/RUSTSEC-2026-0347.html
https://github.com/advisories/GHSA-vp88-798v-h67f
https://github.com/rustls/rustls/pull/3300