CVE-2026-4408

9.0 CRITICAL
Published: May 28, 2026 Modified: June 10, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://access.redhat.com/errata/RHSA-2026:22644
Source: secalert@redhat.com
Issue Tracking
https://access.redhat.com/errata/RHSA-2026:22963
Source: secalert@redhat.com
Issue Tracking
https://access.redhat.com/security/cve/CVE-2026-4408
Source: secalert@redhat.com
Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2479762
Source: secalert@redhat.com
Issue Tracking Third Party Advisory
https://bugzilla.samba.org/show_bug.cgi?id=16034
Source: secalert@redhat.com
Issue Tracking Vendor Advisory

6 reference(s) from NVD

Quick Stats

CVSS v3 Score
9.0 / 10.0
EPSS (Exploit Probability)
1.0%
78th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

samba redhat