RHSA-2026:18160 - Security Advisory

Topic

An update for libssh is now available for Red Hat Enterprise Linux 10.

Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

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 Red Hat Enterprise Linux 10 Release Notes linked from the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 10 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 10.2 x86_64
• Red Hat Enterprise Linux for IBM z Systems 10 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian 10 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.2 ppc64le
• Red Hat Enterprise Linux for ARM 64 10 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.2 aarch64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.2 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.2 s390x
• Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.2 ppc64le
• Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.2 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 10.2 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 10.2 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 10.2 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 10.2 s390x

Fixes

• BZ - 2433121 - CVE-2026-0966 libssh: libssh: Denial of Service via zero-length input in ssh_get_hexa()
• BZ - 2436979 - CVE-2026-0964 libssh: Improper sanitation of paths received from SCP servers
• BZ - 2436980 - CVE-2026-0965 libssh: libssh: Denial of Service via improper configuration file handling
• BZ - 2436981 - CVE-2026-0967 libssh: libssh: Denial of Service via inefficient regular expression processing
• BZ - 2436982 - CVE-2026-0968 libssh: libssh: Denial of Service due to malformed SFTP message
• RHEL-133421 - Rebase libssh to 0.12.0
• RHEL-70825 - Support for hybrid ML-KEM key exchange in libssh
• RHEL-93748 - Wrong log level of messages in RHEL-10.2 and C10s

CVEs

• CVE-2026-0964
• CVE-2026-0965
• CVE-2026-0966
• CVE-2026-0967
• CVE-2026-0968

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/10/html/10.2_release_notes/index