CVE-2026-4408

May 28, 2026, 1:44 p.m.

9.0
Critical

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.

Product(s) Impacted

Vendor Product Versions
Samba
  • Samba
  • Samba-dcerpcd
  • *
  • *

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-78
Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component.

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
a samba samba / / / / / / / /
a samba samba-dcerpcd / / / / / / / /

References

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

Tags

[email protected]
CWE-78
2026-05-28
CVE-2026-4408

CVSS Score

9.0 / 10

CVSS Data - 3.1

  • Attack Vector: NETWORK
  • Attack Complexity: HIGH
  • Privileges Required: NONE
  • Scope: CHANGED
  • Confidentiality Impact: HIGH
  • Integrity Impact: HIGH
  • Availability Impact: HIGH

    • CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

    View Vector String

Timeline

Published: May 28, 2026, 9:16 a.m.
Last Modified: May 28, 2026, 1:44 p.m.

Status : Undergoing Analysis

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.