A path traversal flaw was found in SSSD's AD GPO provider. The ad_gpo_extract_smb_components() function does not sanitize .. sequences in the gPCFileSysPath LDAP attribute, allowing an attacker with AD GPO management access to write files outside the GPO cache directory as root. On default RHEL configurations with SELinux enforcing, this can be used to inject Kerberos configuration leading to authentication bypass.
Set ad_gpo_access_control = disabled in /etc/sssd/sssd.conf to disable GPO fetching entirely. Note that this removes GPO-based login policy enforcement.