RHEL 9 : openssh (RHSA-2026:47756)

critical Nessus Plugin ID 330864

Synopsis

The remote Red Hat host is missing one or more security updates for openssh.

Description

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:47756 advisory.

OpenSSH is an SSH protocol implementation supported by a number of Linux, UNIX, and similar operating systems. It includes the core files necessary for both the OpenSSH client and server.

Security Fix(es):

* openssh: Local MITM of X11 forwarding via abstract UNIX socket pre-binding in Red Hat Enterprise Linux OpenSSH client versions (CVE-2026-55655)

* openssh: Double free in Red Hat Enterprise Linux versions of OpenSSH DH-GEX client path during FIPS known-group validation leads to client-side denial of service (CVE-2026-55653)

* openssh: Heap out-of-bounds read in Red Hat Enterprise Linux versions of OpenSSH GSSAPI indicator cleanup due to missing NULL sentinel termination (CVE-2026-55654)

* openssh: OpenSSH: Use-after-free vulnerability during host key re-exchange on the client side (CVE-2026-60002)

* openssh: OpenSSH: `scp` file misplacement vulnerability during remote copy (CVE-2026-59996)

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.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the RHEL openssh package based on the guidance in RHSA-2026:47756.

Plugin Details

Severity: Critical

ID: 330864

File Name: redhat-RHSA-2026-47756.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 7/30/2026

Updated: 7/30/2026

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.5

Percentile: 57.61

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 9.7

Temporal Score: 7.6

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

CVSS Score Source: CVE-2026-60002

CVSS v3

Risk Factor: Critical

Base Score: 9.4

Temporal Score: 8.4

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

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:9, cpe:/o:redhat:rhel_eus:9.8, p-cpe:/a:redhat:enterprise_linux:openssh-askpass, p-cpe:/a:redhat:enterprise_linux:openssh-clients, p-cpe:/a:redhat:enterprise_linux:openssh-keycat, p-cpe:/a:redhat:enterprise_linux:openssh-server, p-cpe:/a:redhat:enterprise_linux:openssh, p-cpe:/a:redhat:enterprise_linux:pam_ssh_agent_auth

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 7/29/2026

Vulnerability Publication Date: 6/23/2026

Reference Information

CVE: CVE-2026-55653, CVE-2026-55654, CVE-2026-55655, CVE-2026-59996, CVE-2026-60002

CWE: 125, 22, 415, 825, 923

RHSA: 2026:47756

Detections

Analytics