CVE-2026-58050

Name	CVE-2026-58050
Description	libssh2 through 1.11.1 reads an attacker-controlled 32-bit attribute count from a publickey-subsystem response and uses it in the allocation num_attrs * sizeof(libssh2_publickey_attribute) without bounds checking, so on 32-bit platforms the multiplication overflows to an undersized buffer. A malicious SSH server can then drive the attribute-parsing loop to write past the allocation, causing a heap buffer overflow 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)

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	1.11.1-1	vulnerable
	trixie (security)	1.11.1-1+deb13u1	vulnerable
	forky, sid	1.11.1-4	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
libssh2	source	(unstable)	(unfixed)

https://github.com/bikini/exploitarium/tree/main/libssh2-publickey-list-calc-poc