Detections
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TencentOS Server 3: openssh (TSSA-2026:0848)

medium Nessus Plugin ID 335135

Synopsis

The remote TencentOS Server 3 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 3 host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0848 advisory.

 Package updates are available for TencentOS Server 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 Tencent 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

https://mirrors.tencent.com/tlinux/errata/tssa-20260848.xml

Plugin Details

Severity: Medium

ID: 335135

File Name: tencentos_TSSA_2026_0848.nasl

Version: 1.1

Type: Local

Published: 8/13/2026

Updated: 8/13/2026

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:tencent:tencentos_server:3, p-cpe:/a:tencent:tencentos_server:openssh

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/etc/os-release, Host/TencentOS/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 7/30/2026

Vulnerability Publication Date: 6/23/2026

Reference Information

CVE: CVE-2026-55653, CVE-2026-55655