Linux Distros Unpatched Vulnerability : CVE-2026-55654

critical Nessus Plugin ID 322154

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- A flaw was found in OpenSSH. This vulnerability, a heap out-of-bounds read, occurs during the cleanup of GSSAPI (Generic Security Service Application Programming Interface) indicators when a trailing NULL termination is missing in the auth-indicators array. A remote attacker, under specific configurations involving GSSAPI authentication and a Kerberos environment, could exploit this to cause the SSH authentication path to crash or abort. This leads to a denial of service (DoS), impacting the availability of the SSH service. (CVE-2026-55654)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

Plugin Details

Severity: Critical

ID: 322154

File Name: unpatched_CVE_2026_55654.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 6/23/2026

Updated: 6/23/2026

Supported Sensors: Nessus

Risk Information

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:P

CVSS Score Source: CVE-2026-55654

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 8.3

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:openssh-cavs, cpe:/o:redhat:enterprise_linux:6, p-cpe:/a:centos:centos:openssh-ldap, p-cpe:/a:centos:centos:openssh-server, p-cpe:/a:centos:centos:openssh-clients, p-cpe:/a:centos:centos:openssh-server-sysvinit, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:redhat:enterprise_linux:openssh, cpe:/o:centos:centos:8, p-cpe:/a:centos:centos:openssh-keysign, p-cpe:/a:redhat:enterprise_linux:openssh-keycat, p-cpe:/a:redhat:enterprise_linux:pam_ssh_agent_auth, cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:enterprise_linux:10, p-cpe:/a:redhat:enterprise_linux:openssh-server-sysvinit, p-cpe:/a:redhat:enterprise_linux:openssh-keysign, p-cpe:/a:redhat:enterprise_linux:openssh-askpass, p-cpe:/a:centos:centos:openssh-keycat, p-cpe:/a:centos:centos:openssh, p-cpe:/a:centos:centos:openssh-askpass, p-cpe:/a:redhat:enterprise_linux:openssh-clients, cpe:/o:centos:centos:7, cpe:/o:redhat:enterprise_linux:7, p-cpe:/a:redhat:enterprise_linux:openssh-server, p-cpe:/a:redhat:enterprise_linux:openssh-ldap, p-cpe:/a:centos:centos:pam_ssh_agent_auth, p-cpe:/a:centos:centos:openssh-cavs

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 6/23/2026

Reference Information

CVE: CVE-2026-55654

Detections

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