OS Command Injection Affecting samba package, versions <2:4.19.5+dfsg-4ubuntu9.6


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
2.5% (83rd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-UBUNTU2404-SAMBA-16877522
  • published27 May 2026
  • disclosed28 May 2026

Introduced: 27 May 2026

CVE-2026-4408  (opens in a new tab)
CWE-78  (opens in a new tab)

How to fix?

Upgrade Ubuntu:24.04 samba to version 2:4.19.5+dfsg-4ubuntu9.6 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream samba package and not the samba package as distributed by Ubuntu. See How to fix? for Ubuntu:24.04 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1