diff --git a/pkg/webhook/configuration/validating.go b/pkg/webhook/configuration/validating.go
index 7c86aef866c2..e5055c1dea4b 100644
--- a/pkg/webhook/configuration/validating.go
+++ b/pkg/webhook/configuration/validating.go
@@ -27,6 +27,7 @@ import (
 	"k8s.io/apimachinery/pkg/util/validation/field"
 	"k8s.io/apiserver/pkg/util/webhook"
 	"k8s.io/klog/v2"
+	"k8s.io/utils/ptr"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 
 	configv1alpha1 "github.com/karmada-io/karmada/pkg/apis/config/v1alpha1"
@@ -103,7 +104,19 @@ func validateWebhook(hook *configv1alpha1.ResourceInterpreterWebhook, fldPath *f
 	case cc.URL != nil:
 		allErrors = append(allErrors, webhook.ValidateWebhookURL(fldPath.Child("clientConfig").Child("url"), *cc.URL, true)...)
 	case cc.Service != nil:
-		allErrors = append(allErrors, webhook.ValidateWebhookService(fldPath.Child("clientConfig").Child("service"), cc.Service.Name, cc.Service.Namespace, cc.Service.Path, *cc.Service.Port)...)
+		// Temporary fix: If the service port is not specified, set a default value of 443.
+		// This is a workaround to prevent a panic when validating ResourceInterpreterWebhookConfiguration
+		// with an unspecified service port. Ideally, this logic should be handled by a MutatingWebhook,
+		// but introducing a MutatingWebhook at this stage would require significant changes and is not
+		// convenient for cherry-picking to release branches. Therefore, we are temporarily setting the
+		// default port here. Once a MutatingWebhook is implemented, this logic can be moved there.
+		//
+		// Note: The Interpreter framework also sets the same default value (443) when processing Service,
+		// so the backend will not encounter issues due to missing port information.
+		if cc.Service.Port == nil {
+			cc.Service.Port = ptr.To[int32](443)
+		}
+		allErrors = append(allErrors, webhook.ValidateWebhookService(fldPath.Child("clientConfig").Child("service"), cc.Service.Namespace, cc.Service.Name, cc.Service.Path, *cc.Service.Port)...)
 	}
 
 	allErrors = append(allErrors, validateInterpreterContextVersions(hook.InterpreterContextVersions, fldPath.Child("interpreterContextVersions"))...)
diff --git a/pkg/webhook/configuration/validating_test.go b/pkg/webhook/configuration/validating_test.go
index 7097fcf33ade..eb59192949f2 100644
--- a/pkg/webhook/configuration/validating_test.go
+++ b/pkg/webhook/configuration/validating_test.go
@@ -271,6 +271,20 @@ func TestValidateWebhook(t *testing.T) {
 			},
 			expectedError: fmt.Sprintf("must include at least one of %v", strings.Join(acceptedInterpreterContextVersions, ", ")),
 		},
+		{
+			name: "valid webhook configuration: use Service in ClientConfig but with port unspecified",
+			hook: &configv1alpha1.ResourceInterpreterWebhook{
+				Name: "workloads.karmada.io",
+				ClientConfig: admissionregistrationv1.WebhookClientConfig{
+					Service: &admissionregistrationv1.ServiceReference{
+						Namespace: "default",
+						Name:      "svc",
+						Path:      strPtr("/interpreter"),
+					},
+				},
+				InterpreterContextVersions: []string{"v1alpha1"},
+			},
+		},
 	}
 
 	for _, test := range tests {