๐Ÿ” CVE Alert

CVE-2026-4408

CRITICAL 9.0

Samba: remote code execution in samr

CVSS Score
9.0
EPSS Score
0.4%
EPSS Percentile
61th

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.

CWE CWE-78
Vendor red hat
Product red hat enterprise linux 10
Published May 28, 2026
Last Updated Jun 8, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

Affected Versions

Red Hat / Red Hat Enterprise Linux 10
All versions affected
Red Hat / Red Hat Enterprise Linux 8
All versions affected
Red Hat / Red Hat Enterprise Linux 8
All versions affected
Red Hat / Red Hat Enterprise Linux 6
All versions affected
Red Hat / Red Hat Enterprise Linux 6
All versions affected
Red Hat / Red Hat Enterprise Linux 7
All versions affected
Red Hat / Red Hat Enterprise Linux 9
All versions affected
Red Hat / Red Hat OpenShift Container Platform 4
All versions affected

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
access.redhat.com: https://access.redhat.com/errata/RHSA-2026:22644 access.redhat.com: https://access.redhat.com/errata/RHSA-2026:22963 access.redhat.com: https://access.redhat.com/security/cve/CVE-2026-4408 bugzilla.redhat.com: https://bugzilla.redhat.com/show_bug.cgi?id=2479762 bugzilla.samba.org: https://bugzilla.samba.org/show_bug.cgi?id=16034

Credits

Red Hat would like to thank John Walker (ZeroPath) and Ron Ben Yizhak (SafeBreach) for reporting this issue.