CVE-2026-4408

Severity CVSS v4.0:

Pending analysis

Type:

CWE-78 OS Command Injections

Publication date:

28/05/2026

Last modified:

03/07/2026

Description

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 9.00 CRITICAL
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

9.00

Severity 3.x

CRITICAL

Vulnerable products and versions

CPE	From	Up to
cpe:2.3:a:redhat:openshift_container_platform:4.0:::::::*
cpe:2.3:a:samba:samba::::::::	4.1.0 (including)	4.21.0 (excluding)
cpe:2.3:o:redhat:enterprise_linux:6.0:::::::*
cpe:2.3:o:redhat:enterprise_linux:7.0:::::::*
cpe:2.3:o:redhat:enterprise_linux:9.0:::::::*

To consult the complete list of CPE names with products and versions, see this page

CVE-2026-4408

Description

Impact

Vulnerable products and versions

References to Advisories, Solutions, and Tools