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.

Weakness classification

• disclosure@vulncheck.com: CWE-908

Primary references

• disclosure@vulncheck.com — Broken Link
• disclosure@vulncheck.com — Product
• disclosure@vulncheck.com — Third Party Advisory