feat: Env to disable webhook response iframe sandboxing (#17851)

packages/@n8n/config/src/configs/security.config.ts

@@ -38,4 +38,8 @@ export class SecurityConfig {
 	 */
 	@Env('N8N_CONTENT_SECURITY_POLICY_REPORT_ONLY')
 	contentSecurityPolicyReportOnly: boolean = false;
+
+	/** Whether to disable iframe sandboxing for webhooks */
+	@Env('N8N_INSECURE_DISABLE_WEBHOOK_IFRAME_SANDBOX')
+	disableIframeSandboxing: boolean = false;
 }

packages/@n8n/config/test/config.test.ts

@@ -303,6 +303,7 @@ describe('GlobalConfig', () => {
 			daysAbandonedWorkflow: 90,
 			contentSecurityPolicy: '{}',
 			contentSecurityPolicyReportOnly: false,
+			disableIframeSandboxing: false,
 		},
 		executions: {
 			pruneData: true,