CVE-2026-4408

A vulnerability in Samba Active Directory Domain Controller (AD DC) combines LDAP filter injection with improper authorization checks, allowing an authenticated low-privilege domain user to disclose confidential AD attributes such as msKds-RootKeyData, potentially leading to privilege escalation and full domain compromise.

Samba before 4.7.3 might allow remote attackers to obtain sensitive information by leveraging failure of the server to clear allocated heap memory.

In Samba library versions 4.x before 4.2.14, 4.3.x before 4.3.11, and 4.4.x before 4.4.5, a vulnerability allows man-in-the-middle attackers to bypass a client-signing protection mechanism. This enables spoofing of SMB2 and SMB3 servers.

Samba versions 4.x before 4.2.11, 4.3.x before 4.3.8, and 4.4.x before 4.4.2 do not verify X.509 certificates from TLS servers, allowing man-in-the-middle attackers to spoof LDAPS and HTTPS servers and obtain sensitive information via a crafted certificate.

The samldb_check_user_account_control_acl function in Samba 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3 does not properly check for administrative privileges during the creation of machine accounts. This allows remote authenticated users to bypass intended access restrictions.

In Samba versions 3.x and 4.x before 4.1.22, 4.2.x before 4.2.7, and 4.3.x before 4.3.3, a vulnerability allows remote attackers to bypass intended file-access restrictions via a symlink pointing outside of a share when certain substring relationships in share names exist.

The Netlogon server implementation in smbd in Samba 3.5.x and 3.6.x before 3.6.25, 4.0.x before 4.0.25, 4.1.x before 4.1.17, and 4.2.x before 4.2.0rc5 performs a free operation on an uninitialized stack pointer, allowing remote attackers to execute arbitrary code via crafted Netlogon packets.

Samba versions 4.0.x before 4.0.24, 4.1.x before 4.1.16, and 4.2.x before 4.2rc4, when an Active Directory Domain Controller (AD DC) is configured, allow remote authenticated users to set the LDB userAccountControl UF_SERVER_TRUST_ACCOUNT bit, consequently gaining privileges.

A low-privilege authenticated Samba AD user can modify internal LDB special DNs via LDAP access, enabling a domain takeover.

The Samba printing subsystem contains a vulnerability where the client-controlled job description string is passed to the command configured with the 'print command' setting via the '%J' substitution character without escaping shell meta characters. A remote attacker can send a specially crafted print job description containing unescaped shell characters, leading to remote code execution.