CVE-2026-0966

HIGH

Libssh: buffer underflow in ssh_get_hexa() on invalid input

Title source: cna
STIX 2.1

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.

References (6)

Core 6
Core References
Vdb Entry, X_Refsource_Redhat vdb-entry x_refsource_redhat
https://access.redhat.com/security/cve/CVE-2026-0966
Issue Tracking, X_Refsource_Redhat issue-tracking x_refsource_redhat
RHBZ#2433121
https://bugzilla.redhat.com/show_bug.cgi?id=2433121
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:7067
https://access.redhat.com/errata/RHSA-2026:7067
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:18160
https://access.redhat.com/errata/RHSA-2026:18160
Vendor Advisory vendor-advisory x_refsource_redhat
RHSA-2026:18683
https://access.redhat.com/errata/RHSA-2026:18683

Scores

CVSS v3 8.2
EPSS 0.0008
EPSS Percentile 23.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-124
Status published
Products (16)
libssh/libssh < 0.11.4
Red Hat/Red Hat Enterprise Linux 10
Red Hat/Red Hat Enterprise Linux 10 0:0.12.0-2.el10
Red Hat/Red Hat Enterprise Linux 6
Red Hat/Red Hat Enterprise Linux 7
Red Hat/Red Hat Enterprise Linux 8
Red Hat/Red Hat Enterprise Linux 9
Red Hat/Red Hat Enterprise Linux 9 0:0.10.4-18.el9
Red Hat/Red Hat Hardened Images
Red Hat/Red Hat Hardened Images 0.12.0-1.1.hum1
... and 6 more
Published Mar 26, 2026
Tracked Since Mar 27, 2026