CentOS Linux 6 [TuxCare] Security Update: libsmbclient / libsmbclient-devel / samba / samba-client / etc (CENTOS6:CLSA-2026:1781627407)

critical Nessus Plugin ID 361717

Synopsis

The CentOS Linux host is missing one or more security updates.

Description

The CentOS Linux 6 host has packages installed that are affected by a vulnerability as referenced in the TuxCare CENTOS6:CLSA-2026:1781627407 advisory.

- A flaw was found in Samba. A remote attacker can exploit a misconfiguration in Samba file servers and classic domain controllers that use the check password script feature. If this script is configured with the %u substitution character, the client-controlled username is passed without proper escaping of shell meta-characters. This vulnerability allows an attacker to achieve remote command execution on the affected system. This issue primarily affects non-standard configurations where the check password script is used with %u and the samba-dcerpcd service is started as a system service. (CVE-2026-4408)

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 based on the guidance in TuxCare advisory CENTOS6:CLSA-2026:1781627407.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1781627407

http://www.nessus.org/u?6668d5d6

Plugin Details

Severity: Critical

ID: 361717

File Name: tuxcare_centos_6_CLSA-2026-1781627407.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 10/1/2026

Updated: 10/1/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.6

Percentile: 98.35

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-4408

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

Vector: CVSS:3.0/AV:N/AC:L/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

Required KB Items: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list, Host/OS/extended-third-party

Exploit Ease: No known exploits are available

Patch Publication Date: 6/16/2026

Vulnerability Publication Date: 5/28/2026

Reference Information

CVE: CVE-2026-4408

CLSA: 2026:1781627407