CVEs / CVE-2026-4408
CVE-2026-4408: redhat openshift container platform vulnerability
- critical 9.8 CVSS 3.1 (NVD)
- EPSS 46.9% chance of exploitation in the next 30 days, higher than 98% of CVEs (11 Nov 2026)
- Last changed at its sources
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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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| redhat openshift container platform | 4.0 | — |
| samba samba | from 4.1.0, before 4.21.0 | 4.21.0 |
| redhat enterprise linux | 6.0 | — |
| redhat enterprise linux | 7.0 | — |
| redhat enterprise linux | 9.0 | — |
Exploitation
Not in the CISA Known Exploited Vulnerabilities catalog as of 10 Nov 2026.
Severity
| CVSS 3.1 | 9.8 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HScored by NVD |
|---|---|
| Weakness | CWE-78 |
References
- CVE-2026-4408 on NVD
- CVE-2026-4408 on OSV
- https://access.redhat.com/errata/RHSA-2026:22644 Issue Tracking
- https://access.redhat.com/errata/RHSA-2026:22963 Issue Tracking
- https://access.redhat.com/errata/RHSA-2026:25049
- https://access.redhat.com/errata/RHSA-2026:25979
- https://access.redhat.com/errata/RHSA-2026:28053
- https://access.redhat.com/errata/RHSA-2026:28054
- https://access.redhat.com/errata/RHSA-2026:28055
- https://access.redhat.com/errata/RHSA-2026:28056
- https://access.redhat.com/errata/RHSA-2026:28057
- https://access.redhat.com/errata/RHSA-2026:28058
- https://access.redhat.com/errata/RHSA-2026:28132
- https://access.redhat.com/errata/RHSA-2026:29799
- https://access.redhat.com/errata/RHSA-2026:29833
- https://access.redhat.com/errata/RHSA-2026:29863
- https://access.redhat.com/errata/RHSA-2026:56786
- https://access.redhat.com/errata/RHSA-2026:56853
- https://access.redhat.com/errata/RHSA-2026:56911
- https://access.redhat.com/errata/RHSA-2026:57483
- https://access.redhat.com/errata/RHSA-2026:59831
- https://access.redhat.com/errata/RHSA-2026:60019
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.