Samba version 4.0.0 up to 4.5.2 is vulnerable to privilege elevation due to incorrect handling of the PAC (Privilege Attribute Certificate) checksum. A remote, authenticated, attacker can cause the winbindd process to crash using a legitimate Kerberos ticket. A local service with access to the winbindd privileged pipe can cause winbindd to cache elevated access permissions. https://nvd.nist.gov/vuln/detail/CVE-2016-2126