What’s Vulnerable › Vulnerabilities

CVE-2026-0966: Libssh: libssh: denial of service via zero-length input in ssh_get_hexa()

• Severity: high (CVSS 8.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-26 · updated 2026-09-01
• Weakness: CWE-124

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 products

• libssh: before 0.11.4 — fixed in 0.11.4
• Red Hat Enterprise Linux: 8.0, 9.0, 10.0
• RedHat Hardened Images: all versions
• Red Hat OpenShift Container Platform 4.18: 4.0

How to fix

Upgrade to a fixed version: libssh 0.11.4. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2026:18160
• https://access.redhat.com/errata/RHSA-2026:18683
• https://access.redhat.com/errata/RHSA-2026:7067
• https://access.redhat.com/security/cve/CVE-2026-0966
• https://bugzilla.redhat.com/show_bug.cgi?id=2433121
• https://www.libssh.org/2026/02/10/libssh-0-12-0-and-0-11-4-security-releases/

Get alerted when CVE-2026-0966 or the next vulnerability affects your stack