Remote Command Execution Vulnerability in Samba File Servers and Domain Controllers
CVE-2026-4408

9CRITICAL

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Vendor
CVE Published:
28 May 2026

What is CVE-2026-4408?

A significant flaw exists in Samba, particularly affecting file servers and classic domain controllers that utilize the 'check password script' feature. When configured with the %u substitution character, this vulnerability allows remote attackers to execute commands by exploiting improper handling of user input. The exploit is most potent in non-standard configurations where this feature is active, leading to the possibility of remote command execution through the samba-dcerpcd service, potentially compromising system integrity.

References

https://access.redhat.com/security/cve/CVE-2026-4408
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2479762
issue-trackingx_refsource_REDHAT
https://bugzilla.samba.org/show_bug.cgi?id=16034

CVSS V3.1

Score:
9
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.