Detections
Analytics

TencentOS Server 3: openssh (TSSA-2026:0392)

high Nessus Plugin ID 324637

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-2026:0392 advisory.

 Package updates are available for TencentOS Server 3 that fix the following vulnerabilities:

 CVE-2026-35385:
 A flaw was found in OpenSSH. When the `scp` command is used by a root user to download a file with the legacy protocol option (`-O`) and without preserving original file permissions (`-p`), the downloaded file can be installed with elevated privileges (setuid or setgid). This unexpected behavior could allow a malicious file to execute with higher permissions than intended, posing a security risk through potential privilege escalation.

 CVE-2026-35386:
 A flaw was found in OpenSSH. This vulnerability allows a remote attacker to achieve arbitrary command execution by injecting shell metacharacters into a username provided on the command line. Exploitation requires an untrusted username and a non-default configuration of the '%' character in `ssh_config`.

 CVE-2026-35387:
 A flaw was found in OpenSSH. This vulnerability allows the system to use unintended Elliptic Curve Digital Signature Algorithm (ECDSA) algorithms. This occurs because the configuration for accepted public key algorithms is misinterpreted, leading to the use of weaker cryptographic methods than intended. This could potentially allow an attacker to compromise the confidentiality of data.

 CVE-2026-35388:
 A flaw was found in OpenSSH. This vulnerability allows for a low integrity impact due to the omission of connection multiplexing confirmation for proxy-mode multiplexing sessions. A local user, under specific and complex conditions requiring user interaction, could potentially establish a multiplexed session without explicit confirmation, leading to unintended data handling.

 CVE-2026-35414:
 A flaw was found in OpenSSH. This vulnerability arises from the incorrect handling of the authorized_keys principals option in uncommon scenarios. Specifically, when a principals list is used with a Certificate Authority that includes comma characters, OpenSSH may misinterpret the input. This could lead to security bypasses, potentially allowing unintended access or information disclosure in specific authentication contexts.

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-20260392.xml

Plugin Details

Severity: High

ID: 324637

File Name: tencentos_TSSA_2026_0392.nasl

Version: 1.1

Type: Local

Published: 7/2/2026

Updated: 7/2/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.92

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 5.6

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

CVSS Score Source: CVE-2026-35414

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.1

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

Temporal Vector: CVSS:3.0/E:U/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 Ease: No known exploits are available

Patch Publication Date: 5/4/2026

Vulnerability Publication Date: 4/2/2026

Reference Information

CVE: CVE-2026-35385, CVE-2026-35386, CVE-2026-35387, CVE-2026-35388, CVE-2026-35414

IAVA: 2026-A-0296