Detections
Analytics
Alibaba Cloud Linux 3 : 0246: openssh (ALINUX3-SA-2026:0246)
medium Nessus Plugin ID 333568
Synopsis
The remote Alibaba Cloud Linux host is missing one or more security updates.Description
The remote Alibaba Cloud Linux 3 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALINUX3-SA-2026:0246 advisory.Package updates are available for Alibaba Cloud Linux 3 that fix the following vulnerabilities:
CVE-2026-55653:
A flaw was found in OpenSSH. A malicious SSH server can exploit a double free vulnerability in the Diffie- Hellman Group Exchange (DH-GEX) client path. This occurs during FIPS (Federal Information Processing Standards) mode known-group validation when the client processes attacker-controlled DH-GEX group parameters. Successful exploitation leads to client-side process termination, resulting in a Denial of Service (DoS).
CVE-2026-55655:
A flaw was found in OpenSSH. A local unprivileged attacker on a Linux client host can hijack client-side X11 forwarding connections. This is possible by pre-binding the preferred abstract X socket name when X11 forwarding is enabled and a local UNIX-domain X socket is used. A successful attack can compromise the confidentiality of forwarded X11 traffic, including sensitive window contents and input, and may allow some manipulation of the forwarded session.
Tenable has extracted the preceding description block directly from the Alibaba Cloud 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 affected packages.See Also
http://mirrors.aliyun.com/alinux/3/cve/alinux3-sa-20260246.xml
Plugin Details
Severity: Medium
ID: 333568
File Name: alinux3_sa_2026-0246.nasl
Version: 1.1
Type: Local
Published: 8/10/2026
Updated: 8/10/2026
Supported Sensors: Nessus
Risk Information
VPR
Risk Factor: Low
Score: 3.5
Percentile: 51.86
CVSS v2
Risk Factor: Medium
Base Score: 5.6
Temporal Score: 4.4
Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:P/A:N
CVSS Score Source: CVE-2026-55655
CVSS v3
Risk Factor: Medium
Base Score: 6.1
Temporal Score: 5.5
Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:L/A:N
Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C
Vulnerability Information
CPE: cpe:/o:alibabacloud:alibaba_cloud_linux_3, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:openssh-askpass, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:openssh-cavs, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:openssh-clients, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:openssh-keycat, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:openssh-ldap, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:openssh-server, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:openssh, p-cpe:/a:alibabacloud:alibaba_cloud_linux_3:pam_ssh_agent_auth
Required KB Items: Host/local_checks_enabled, Host/Alibaba/release, Host/Alibaba/rpm-list, Host/cpu
Exploit Available: true
Exploit Ease: Exploits are available
Patch Publication Date: 8/5/2026
Vulnerability Publication Date: 6/23/2026
Reference Information
CVE: CVE-2026-55653, CVE-2026-55655