Attack Chain

1. An attacker gains or already possesses valid Active Directory GPO management credentials and access.
2. Using their GPO management privileges, the attacker modifies the gPCFileSysPath LDAP attribute to include .. path traversal sequences.
3. The crafted gPCFileSysPath attribute is designed to point to a sensitive system directory outside the normal GPO cache on the target SSSD-managed RHEL system.
4. When SSSD's ad_gpo_extract_smb_components() function processes this attribute, it inadequately sanitizes the .. sequences, misinterpreting the attacker's intended path.
5. This allows the attacker to write arbitrary files with root privileges to a chosen location on the affected RHEL system, bypassing normal file system permissions.
6. The attacker injects a malicious Kerberos configuration file (e.g., within /etc/krb5.conf.d/ or /etc/krb5.conf) into a directory that is processed by the system's Kerberos client.
7. The injected configuration manipulates Kerberos authentication parameters, potentially redirecting authentication requests or enabling compromise of Kerberos tickets.
8. This manipulation leads to an authentication bypass, granting the attacker unauthorized access or elevated privileges on the SSSD-managed RHEL system.

Impact

Successful exploitation of CVE-2026-14476 grants an authenticated attacker (with AD GPO management access) the ability to achieve arbitrary file write as root on targeted Red Hat Enterprise Linux systems. This level of access allows for critical system compromise, including the injection of malicious Kerberos configurations that can lead to a full authentication bypass. The consequence is a complete compromise of system integrity, confidentiality, and availability, enabling unauthorized access to sensitive data and critical system functions. Organizations relying on SSSD for Active Directory integration on RHEL are at risk, with potential for widespread compromise if AD GPO management systems are breached.

Recommendation

• Patch CVE-2026-14476 by applying the latest security updates provided by Red Hat for SSSD to all affected Red Hat Enterprise Linux and OpenShift Container Platform installations.
• Review and restrict Active Directory GPO management access to only necessary administrative accounts, following the principle of least privilege.
• Monitor for unusual file creation or modification events in sensitive system directories (e.g., /etc/krb5.conf, /etc/krb5.conf.d/) on SSSD-managed RHEL systems.
• Implement host-based intrusion detection systems to alert on unexpected changes to Kerberos configuration files or attempts to write files outside standard GPO cache locations.