Vulnerability · Published Mar 26, 2026 · Assigned by redhat
CVE-2026-0966Libssh: libssh: denial of service via zero-length input in ssh_get_hexa()
Medium 6.5
In plain English
A medium-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | libssh | 0.12.0-2.el10 | ALSA-2026:18160 |
| AlmaLinux:9 | libssh | 0.10.4-18.el9 | ALSA-2026:18683 |
| AlmaLinux:10 | libssh-config | 0.12.0-2.el10 | ALSA-2026:18160 |
| AlmaLinux:9 | libssh-config | 0.10.4-18.el9 | ALSA-2026:18683 |
| AlmaLinux:10 | libssh-devel | 0.12.0-2.el10 | ALSA-2026:18160 |
| AlmaLinux:9 | libssh-devel | 0.10.4-18.el9 | ALSA-2026:18683 |
| Alpine:v3.23 | libssh | 0.11.4-r0 | ALPINE-CVE-2026-0966 |
| Alpine:v3.24 | libssh | 0.12.0-r0 | ALPINE-CVE-2026-0966 |
| Debian:12 | libssh | 0.10.6-0+deb12u3 | DEBIAN-CVE-2026-0966 |
| Debian:13 | libssh | 0.11.5-0+deb13u1 | DEBIAN-CVE-2026-0966 |
| Debian:14 | libssh | 0.12.0-1 | DEBIAN-CVE-2026-0966 |
| Rocky Linux:10 | libssh | 0:0.12.0-2.el10 | RLSA-2026:18160 |
| Rocky Linux:9 | libssh | 0:0.10.4-18.el9 | RLSA-2026:18683 |
| Ubuntu:22.04:LTS | libssh | 0.9.6-2ubuntu0.22.04.6 | UBUNTU-CVE-2026-0966 |
| Ubuntu:22.04:LTS | libssh | 0.9.6-2ubuntu0.22.04.6 | USN-8051-1 |
| Ubuntu:24.04:LTS | libssh | 0.10.6-2ubuntu0.3 | USN-8051-1 |
| Ubuntu:24.04:LTS | libssh | 0.10.6-2ubuntu0.3 | UBUNTU-CVE-2026-0966 |
| Ubuntu:25.10 | libssh | 0.11.2-1ubuntu0.2 | UBUNTU-CVE-2026-0966 |
| Ubuntu:25.10 | libssh | 0.11.2-1ubuntu0.2 | USN-8051-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat Hardened Images | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Hardened Images | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
Weakness: CWE-124 · Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
References
- RHSA-2026:18160 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:18683 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:7067 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-0966 vdb-entry, x_refsource_REDHAT
- RHBZ#2433121 issue-tracking, x_refsource_REDHAT
- https://www.libssh.org/2026/02/10/libssh-0-12-0-and-0-11-4-security-releases/