Detections
Analytics

TencentOS Server 4: cifs-utils (TSSA-2026:0552)

high Nessus Plugin ID 325858

Synopsis

The remote TencentOS Server 4 host is missing one or more security updates.

Description

The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2026:0552 advisory.

 Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

 CVE-2026-12505:
 A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This forces the system to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary commands as the root user, elevating their privileges and fully compromising the system.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for this issue 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-20260552.xml

Plugin Details

Severity: High

ID: 325858

File Name: tencentos_TSSA_2026_0552.nasl

Version: 1.1

Type: Local

Published: 7/9/2026

Updated: 7/9/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.04

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2026-12505

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/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:4, p-cpe:/a:tencent:tencentos_server:cifs-utils

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

Exploit Ease: No known exploits are available

Patch Publication Date: 7/6/2026

Vulnerability Publication Date: 6/9/2026

Reference Information

CVE: CVE-2026-12505

IAVB: 2026-B-0164