CVE-2026-4408
Samba: remote code execution in samr
Updated
- CVSS 3.1
- 9.0 CRITICAL
- EPSS
- 46.9% (99th pct)
- CISA KEV
- Not listed
- Published
- 2026-05-28
- Weakness
- CWE-78
- Ports
- 139 NetBIOS-SSN, 445 SMB
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.
Key Findings
as of 2026-11-12- Its current EPSS score (46.9%) is higher than that of 47% of CISA KEV entries.
Severity
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:HOpen in CVSS calculator Affected Products
| Vendor | Product | Affected versions |
|---|---|---|
| Red Hat | Red Hat Red Hat Enterprise Linux 10 | 0:4.23.5-109.el10_2 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support | 0:4.21.3-114.el10_0.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support | 0:4.10.16-26.el7_9.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support | 0:4.10.16-26.el7_9.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 8 | 0:4.19.4-16.el8_10 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 8 | 0:4.19.4-16.el8_10 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support | 0:4.13.3-12.el8_4.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On | 0:4.13.3-12.el8_4.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | 0:4.15.5-16.el8_6.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | 0:4.15.5-16.el8_6.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service | 0:4.17.5-7.el8_8.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | 0:4.17.5-7.el8_8.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 9 | 0:4.23.5-10.el9_8 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 9 | 0:4.23.5-10.el9_8 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | 0:4.17.5-105.el9_2.5 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | 0:4.19.4-105.el9_4.4 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support | 0:4.21.3-14.el9_6.1 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.12 | 412.86.202608241157-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.13 | 413.92.202609080414-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.14 | 414.92.202608172040-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.15 | 415.92.202608180329-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.16 | 416.94.202608150307-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.17 | 417.94.202608250221-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.18 | 418.94.202608142238-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.19 | 4.19.9.6.202606241344-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.20 | 4.20.9.6.202606241928-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat OpenShift Container Platform 4.21 | 4.21.9.6.202606241859-0 to <* (unaffected) |
| Red Hat | Red Hat Red Hat Enterprise Linux 6 | - |
| Red Hat | Red Hat Red Hat Enterprise Linux 6 | - |
References
24 linksVendor advisories
- RHSA-2026:22644
- RHSA-2026:22963
- RHSA-2026:25049
- RHSA-2026:25979
- RHSA-2026:28053
- RHSA-2026:28054
- RHSA-2026:28055
- RHSA-2026:28056
- RHSA-2026:28057
- RHSA-2026:28058
- RHSA-2026:28132
- RHSA-2026:29799
- RHSA-2026:29833
- RHSA-2026:29863
- RHSA-2026:56786
- RHSA-2026:56853
- RHSA-2026:56911
- RHSA-2026:57483
- RHSA-2026:59831
- RHSA-2026:60019
- RHSA-2026:65839
Vulnerability databases
Issue trackers
Other references
Record Details
- Published
- 2026-05-28
- Last updated
- 2026-11-04
- Assigner (CNA)
- redhat
- Credited to
- Red Hat would like to thank John Walker (ZeroPath) and Ron Ben Yizhak (SafeBreach) for reporting this issue.
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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). Alert titles and links from CISA cybersecurity alerts. This site is not affiliated with or endorsed by MITRE, NVD, CISA, or FIRST.