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.
https://bugzilla.redhat.com/show_bug.cgi?id=2479762
https://access.redhat.com/security/cve/CVE-2026-4408
https://access.redhat.com/errata/RHSA-2026:29863
https://access.redhat.com/errata/RHSA-2026:29833
https://access.redhat.com/errata/RHSA-2026:29799
https://access.redhat.com/errata/RHSA-2026:28132
https://access.redhat.com/errata/RHSA-2026:28058
https://access.redhat.com/errata/RHSA-2026:28057
https://access.redhat.com/errata/RHSA-2026:28056
https://access.redhat.com/errata/RHSA-2026:28055
https://access.redhat.com/errata/RHSA-2026:28054
https://access.redhat.com/errata/RHSA-2026:28053
https://access.redhat.com/errata/RHSA-2026:25979
https://access.redhat.com/errata/RHSA-2026:25049