CVE-2026-58051

Name	CVE-2026-58051
Description	libssh2 through 1.11.1 grows its publickey list with SSH2_REALLOC but does not zero-initialize new entries before parsing populates them, so a parse failure reaching the cleanup path leaves libssh2_publickey_list_free operating on an uninitialized entry. A malicious SSH server offering the publickey subsystem can use a malformed response to make cleanup free an uninitialized, attacker-influenceable attrs pointer in a connecting libssh2 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)
Debian Bugs	1144415

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
libssh2 (PTS)	bullseye	1.9.0-2+deb11u1	vulnerable
	bookworm	1.10.0-3	vulnerable
	trixie (security), trixie	1.11.1-1+deb13u1	vulnerable
	forky, sid	1.11.1-6	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
libssh2	source	(unstable)	1.11.1-6			1144415

Notes

[trixie] - libssh2 <no-dsa> (Minor issue; can be fixed via point release)
https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc
https://github.com/libssh2/libssh2/pull/2127
Fixed by: https://github.com/libssh2/libssh2/commit/a9758da45a52bc8c630ec9493804d0c6ea30b24a