ServiceNow REST Message 403 Forbidden on Genesys Cloud PII Masking Webhook

Could someone explain the correct authentication handshake required when a Genesys Cloud Data Action triggers a ServiceNow REST Message specifically for GDPR/CCPA data masking? We are running into a persistent 403 Forbidden error that is not related to standard IAM permissions, as the same endpoint works perfectly when tested via Postman using basic auth.

Our environment is Genesys Cloud v24.4.0 in the eu-west-1 region. The Architect flow captures the conversation transcript and triggers a Data Action to POST to our ServiceNow instance (Washington DC release). The payload contains the conversation_id, agent_id, and a list of pii_elements that need to be redacted in the associated ServiceNow incident.

The ServiceNow side is configured with a REST Message that uses Basic Authentication. However, the Genesys Cloud Data Action is failing at the outbound stage. The error log in ServiceNow shows:

{"error": {"message": "Forbidden", "status": 403, "detail": "Invalid credentials or scope mismatch for table incident."}}

I have verified that the ServiceNow user account has the sn_data_masking plugin installed and the role data_masking_admin assigned. The Genesys Cloud webhook is configured to pass the username and password in the Authorization header using basic auth encoding. I suspect the issue might be related to how Genesys Cloud handles the User-Agent string or specific IP allow-listing requirements on the ServiceNow side that are blocking the Genesys Cloud egress IPs.

Has anyone successfully integrated Genesys Cloud Data Actions with ServiceNow REST Messages for compliance workflows? Specifically, are there any known issues with the Content-Type: application/json header being stripped or malformed by the Genesys Cloud webhook service? I am cross-referencing the ServiceNow IntegrationHub docs but cannot find a specific mention of Genesys Cloud egress behavior.