Affected: AlmaLinux:10: libssh, AlmaLinux:10: libssh-config, AlmaLinux:10: libssh-devel

libssh is a library which implements the SSH protocol. It can be used to implement client and server applications.

Security Fix(es):

* libssh: Buffer underflow in ssh_get_hexa() on invalid input (CVE-2026-0966) * libssh: Improper sanitation of paths received from SCP servers (CVE-2026-0964) * libssh: libssh: Denial of Service via improper configuration file handling (CVE-2026-0965) * libssh: libssh: Denial of Service via inefficient regular expression processing (CVE-2026-0967) * libssh: libssh: Denial of Service due to malformed SFTP message (CVE-2026-0968)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Additional Changes:

For detailed information on changes in this release, see the AlmaLinux Release Notes linked from the References section.

Affected: Alpaquita:23: libssh, Alpaquita:25: libssh, Alpaquita:stream: libssh

A flaw was found in libssh. The API function `ssh_get_hexa()` is vulnerable to a denial of service when processing zero-length input. This can be exploited remotely by an attacker during GSSAPI (Generic Security Service Application Program Interface) authentication if the server's logging verbosity is set to `SSH_LOG_PACKET (3)` or higher. Successful exploitation could lead to a self-Denial of Service of the per-connection daemon process.

The API function `ssh_get_hexa()` is vulnerable, when 0-lenght input is provided to this function. This function is used internally in `ssh_get_fingerprint_hash()` and `ssh_print_hexa()` (deprecated), which is vulnerable to the same input (length is provided by the calling application).

The function is also used internally in the gssapi code for logging the OIDs received by the server during GSSAPI authentication. This could be triggered remotely, when the server allows GSSAPI authentication and logging verbosity is set at least to SSH_LOG_PACKET (3). This could cause self-DoS of the per-connection daemon process.

Affected: openEuler:24.03-LTS-SP1: libssh

The ssh library was designed to be used by programmers needing a working SSH implementation by the mean of a library. The complete control of the client is made by the programmer. With libssh, you can remotely execute programs, transfer files, use a secure and transparent tunnel for your remote programs. With its Secure FTP implementation, you can play with remote files easily, without third-party programs others than libcrypto (from openssl). Security Fix(es):

(CVE-2026-0964)

(CVE-2026-0965)

(CVE-2026-0966)

(CVE-2026-0967)

(CVE-2026-0968)

libssh-config-0.11.4-1.1 on GA media

libssh: libssh: Insecure default configuration leads to local man-in-the-middle attacks on Windows libssh: libssh: Denial of Service via zero-length input in ssh_get_hexa() libssh: libssh: Denial of Service via out-of-bounds read in SFTP extension name handler

Security update for libssh

Affected: Ubuntu:Pro:16.04:LTS: libssh, Ubuntu:Pro:18.04:LTS: libssh, Ubuntu:Pro:20.04:LTS: libssh, Ubuntu:22.04:LTS: libssh, Ubuntu:24.04:LTS: libssh, Ubuntu:25.10: libssh

A flaw was found in libssh. The API function `ssh_get_hexa()` is vulnerable to a denial of service when processing zero-length input. This can be exploited remotely by an attacker during GSSAPI (Generic Security Service Application Program Interface) authentication if the server's logging verbosity is set to `SSH_LOG_PACKET (3)` or higher. Successful exploitation could lead to a self-Denial of Service of the per-connection daemon process.

Ein Angreifer kann mehrere Schwachstellen in libssh ausnutzen, um Dateien zu manipulieren oder um einen Denial-of-Service-Zustand zu verursachen.