CVE-2026-58051

A flaw in libssh2 allows a malicious SSH server to send a malformed public key response, triggering an invalid memory cleanup. This can cause the connecting client application to crash or leak information.

Moderate: This flaw in libssh2 can lead to a denial of service or information disclosure in client applications when connecting to a malicious SSH server. The vulnerability arises from improper handling of uninitialized memory during public key list processing, which an attacker can trigger with a specially crafted response. Exploitation requires active interaction with a compromised or malicious server, limiting the attack surface to untrusted connections.

Note: Red Hat Enterprise Linux (RHEL) 8 and newer are not affected by this flaw, as they do not ship the libssh2 package.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, ensure your applications connect only to trusted and verified SSH servers. For added protection, maintain standard system memory defenses to automatically intercept and safely terminate any processes corrupted by an unexpected server error.