diff --git a/ruoyi-common/src/main/java/com/ruoyi/common/utils/RequestUrlUtils.java b/ruoyi-common/src/main/java/com/ruoyi/common/utils/RequestUrlUtils.java
index db8f00e..06a3d3d 100644
--- a/ruoyi-common/src/main/java/com/ruoyi/common/utils/RequestUrlUtils.java
+++ b/ruoyi-common/src/main/java/com/ruoyi/common/utils/RequestUrlUtils.java
@@ -71,8 +71,11 @@ public final class RequestUrlUtils
         String normalized = host.trim().toLowerCase();
         if (normalized.startsWith("[") && normalized.contains("]")) {
             normalized = normalized.substring(1, normalized.indexOf(']'));
-        } else if (normalized.indexOf(':') == normalized.lastIndexOf(':')) {
-            normalized = normalized.substring(0, normalized.indexOf(':'));
+        } else {
+            int portSeparator = normalized.lastIndexOf(':');
+            if (portSeparator > -1 && normalized.indexOf(':') == portSeparator) {
+                normalized = normalized.substring(0, portSeparator);
+            }
         }
         return "localhost".equals(normalized)
                 || "127.0.0.1".equals(normalized)