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.
References
- www.cve.org/CVERecord ↗
- nvd.nist.gov/vuln/detail/CVE-2026-4408 ↗
- access.redhat.com/errata/RHSA-2026:22644 ↗
- access.redhat.com/errata/RHSA-2026:22963 ↗
- access.redhat.com/errata/RHSA-2026:25049 ↗
- access.redhat.com/errata/RHSA-2026:25979 ↗
- access.redhat.com/errata/RHSA-2026:28053 ↗
- access.redhat.com/errata/RHSA-2026:28054 ↗
- access.redhat.com/errata/RHSA-2026:28055 ↗
- access.redhat.com/errata/RHSA-2026:28056 ↗
- access.redhat.com/errata/RHSA-2026:28057 ↗
- access.redhat.com/errata/RHSA-2026:28058 ↗
- access.redhat.com/errata/RHSA-2026:28132 ↗
- access.redhat.com/errata/RHSA-2026:29799 ↗
- access.redhat.com/errata/RHSA-2026:29833 ↗
- access.redhat.com/errata/RHSA-2026:29863 ↗
- access.redhat.com/errata/RHSA-2026:56786 ↗
- access.redhat.com/errata/RHSA-2026:56853 ↗
- access.redhat.com/errata/RHSA-2026:56911 ↗
- access.redhat.com/errata/RHSA-2026:57483 ↗
- access.redhat.com/errata/RHSA-2026:59831 ↗
- access.redhat.com/errata/RHSA-2026:60019 ↗
- access.redhat.com/errata/RHSA-2026:65839 ↗
- access.redhat.com/security/cve/CVE-2026-4408 ↗
- bugzilla.redhat.com/show_bug.cgi ↗
- bugzilla.samba.org/show_bug.cgi ↗
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4408.json ↗
Related CVEs
← CVE Index: search every CVE from the last 30 days
This product uses the NVD API but is not endorsed or certified by the NVD. CVSS scores do not establish exploitation.