CVE-2026-58051

CVE-2026-58051 is a high-severity vulnerability rated 8.3/10 on the CVSS scale. 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.. EPSS estimates a 0.28% chance of exploitation in the next 30 days.