Certificate chain validation failed: untrusted root CA

The root Certificate Authority that signed the target server's SSL certificate is not present in ServiceNow's Java truststore, which is the most common scenario for custom or internal CAs. (high likelihood)

The target server is presenting an incomplete certificate chain that doesn't include intermediate certificates needed to establish trust back to a known root CA. (high likelihood)

ServiceNow's Java truststore has been modified or corrupted, removing standard root CAs that should be trusted by default. (medium likelihood)

The target server is using a self-signed certificate that hasn't been explicitly imported into ServiceNow's truststore as a trusted certificate. (medium likelihood)

Certificate validation is being enforced by system property changes when it was previously bypassed, revealing existing trust issues. (low likelihood)

Step 1: Navigate to System Definition > Certificates to view existing certificates and identify if the required CA certificate is already imported.

Step 2: Obtain the root CA certificate from your certificate authority or extract it from the target server using openssl or browser tools in PEM or DER format.

Step 3: Go to System Definition > Certificates and click New to import the CA certificate, ensuring the Format field matches your certificate file type.

Step 4: Set the Type field to Trust Store Certificate and provide a descriptive name in the Name field for future reference.

Step 5: Paste the certificate content into the PEM Certificate field or upload the certificate file, then click Submit to save.

Step 6: If intermediate certificates are required, repeat the import process for each certificate in the chain from intermediate to root CA.

Step 7: Test the connection by retrying the failed integration or using REST API Explorer to verify SSL handshake completes successfully.

Step 8: Check System Diagnostics > Log > Application Log for any remaining certificate validation errors and verify the error no longer appears.