CVE-2026-0967

Name	CVE-2026-0967
Description	A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client.
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)
References	DSA-6410-1
Debian Bugs	1127693

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
libssh (PTS)	bookworm	0.10.6-0+deb12u2	vulnerable
	bookworm (security)	0.10.6-0+deb12u1	vulnerable
	trixie	0.11.2-1+deb13u1	vulnerable
	trixie (security)	0.11.5-0+deb13u1	fixed
	forky, sid	0.12.2-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
libssh	source	trixie	0.11.5-0+deb13u1		DSA-6410-1
libssh	source	(unstable)	0.12.0-1			1127693

Notes

[bookworm] - libssh <no-dsa> (Minor issue)
[bullseye] - libssh <postponed> (Minor issue)
https://www.libssh.org/security/advisories/CVE-2026-0967.txt
Fixed by: https://git.libssh.org/projects/libssh.git/commit/?id=6d74aa6138895b3662bade9bd578338b0c4f8a15 (libssh-0.11.4)