Fnbam_denied

Understanding why the error appears requires looking at the security architecture of modern banking apps. Here are the primary causes:

: Use the diagnose test authserver command to verify if the FortiGate can talk to your RADIUS/LDAP server independently of the VPN tunnel.

: If this occurs on a physical port, refer to the Troubleshooting Tip: 802.1x auth failing on the Fortinet community site to check for match condition errors. fnbam_denied

: The user authenticated successfully against a backend (like RADIUS or LDAP), but they do not belong to the specific user group allowed in the FortiGate policy.

LDAP error 49 (invalid credentials) or an expired user account. Understanding why the error appears requires looking at

: If using SAML, missing or mismatched "username" and "groups" assertion attributes in the Identity Provider (IdP) can trigger a denial.

: To see the exact reason for the denial, run the following commands in the FortiGate CLI while attempting to connect: diagnose debug application fnbamd -1 diagnose debug enable Use code with caution. Copied to clipboard : The user authenticated successfully against a backend

IR-2026-04-14-001 Date of Event: 2026-04-14 Report Generated: 2026-04-14 10:30 AM (UTC) Severity: Medium (Access Control Violation)

Decoding "fnbam_denied": Understanding Access Restrictions and System Blocks in Digital Banking

Ensure the RADIUS policy allows OTP and that the FortiGate is configured for EAP. Scenario B: FortiClient 7.4.3 GA Bug

To fix the FNBAM_DENIED error, follow these troubleshooting steps, typically performed via the CLI on your FortiGate firewall. 1. Enable Debug Logs