Affected: libssh, Red Hat Enterprise Linux 9, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat OpenShift Container Platform 4

A flaw was found in libssh's handling of key exchange (KEX) processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when using libgcrypt, which impacts application stability and availability.

Affected: Ubuntu:22.04:LTS: libssh, Ubuntu:24.04:LTS: libssh, Ubuntu:25.10: libssh

It was discovered that libssh clients incorrectly handled the key exchange process. A remote attacker could possibly use this issue to cause libssh clients to crash, resulting in a denial of service. (CVE-2025-8277)

It was discovered that the libssh SCP client incorrectly sanitized paths received from servers. A remote attacker could use this issue to cause libssh SCP clients to overwrite files outside of the working directory and possibly execute arbitrary code. (CVE-2026-0964)

It was discovered that libssh incorrectly handled parsing configuration files. A local attacker could possibly use this issue to cause libssh to access non-regular files, resulting in a denial of service. (CVE-2026-0965)

It was discovered that libssh incorrectly handled the ssh_get_hexa() function. A remote attacker could possibly use this issue to cause libssh to crash, resulting in a denial of service. (CVE-2026-0966)

It was discovered that libssh incorrectly handled certain regular expressions. A local attacker could possibly use this issue to cause libssh to consume resources, resulting in a denial of service. (CVE-2026-0967)

It was discovered that the libssh SFTP client incorrectly handled certain malformed longname fields. A remote attacker could use this issue to cause libssh SFTP clients to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2026-0968)