Vulnerability Intelligence Report
Samba: remote code execution in samr
CVE-2026-4408
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.
Injection
No Active Exploit Signals
CVSS Base Score
9.0
CRITICAL
Exploitability:2.3
Impact Score:6.1
EPSS Probability:2.50%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
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Authentication
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Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-78 ↗Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | 0:4.23.5-109.el10_2 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | 0:4.21.3-114.el10_0.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 7 Extended Lifecycle Support | 0:4.10.16-26.el7_9.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 7 Extended Lifecycle Support | 0:4.10.16-26.el7_9.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 8 | 0:4.19.4-16.el8_10 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 8 | 0:4.19.4-16.el8_10 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | 0:4.13.3-12.el8_4.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | 0:4.13.3-12.el8_4.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | 0:4.15.5-16.el8_6.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | 0:4.15.5-16.el8_6.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | 0:4.17.5-7.el8_8.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | 0:4.17.5-7.el8_8.1 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 9 | 0:4.23.5-10.el9_8 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 9 | 0:4.23.5-10.el9_8 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | 0:4.17.5-105.el9_2.5 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | 0:4.19.4-105.el9_4.4 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | 0:4.21.3-14.el9_6.1 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.12 | 412.86.202608241157-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.13 | 413.92.202609080414-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.14 | 414.92.202608172040-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.15 | 415.92.202608180329-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.16 | 416.94.202608150307-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.17 | 417.94.202608250221-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.18 | 418.94.202608142238-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.19 | 4.19.9.6.202606241344-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.20 | 4.20.9.6.202606241928-0 < * (unaffected) |
| Red Hat | Red Hat OpenShift Container Platform 4.21 | 4.21.9.6.202606241859-0 < * (unaffected) |
| Red Hat | Red Hat Enterprise Linux 6 | all |
| Red Hat | Red Hat Enterprise Linux 6 | all |
| Red Hat | Red Hat OpenShift Container Platform 4 | all |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Red Hat, Inc. · Vendor · USA |
| Reserved | 2026-03-18T21:40:14 |
| Published | 2026-05-28T07:25:27 |
| Patch Date | 2026-05-26 |
| Last Updated | 2026-09-18T12:04:44 |
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