diff --git a/src/main/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInput.kt b/src/main/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInput.kt
index 4eb9ecfe..d4b39657 100644
--- a/src/main/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInput.kt
+++ b/src/main/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInput.kt
@@ -158,7 +158,11 @@ data class ClusterMetricsInput(
         return if (url.isEmpty()) {
             constructUrlFromInputs()
         } else {
-            URIBuilder(url).build()
+            try {
+                URIBuilder(url).build()
+            } catch (e: URISyntaxException) {
+                throw IllegalArgumentException("Invalid URL syntax.")
+            }
         }
     }
 
@@ -243,7 +247,11 @@ data class ClusterMetricsInput(
                 .setHost(SUPPORTED_HOST)
                 .setPort(SUPPORTED_PORT)
                 .setPath(path + pathParams)
-            uriBuilder.build()
+            try {
+                uriBuilder.build()
+            } catch (e: URISyntaxException) {
+                throw IllegalArgumentException("Invalid URL syntax.")
+            }
         }
     }
 
diff --git a/src/test/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInputTests.kt b/src/test/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInputTests.kt
index 0e739e7f..6d1c1055 100644
--- a/src/test/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInputTests.kt
+++ b/src/test/kotlin/org/opensearch/commons/alerting/model/ClusterMetricsInputTests.kt
@@ -555,4 +555,40 @@ class ClusterMetricsInputTests {
             )
         }
     }
+
+    @Test
+    fun `test url field contains invalid characters`() {
+        // GIVEN
+        path = ""
+        pathParams = ""
+        url = "http://localhost:9200/${ILLEGAL_PATH_PARAMETER_CHARACTERS.joinToString("")}"
+
+        // WHEN + THEN
+        assertFailsWith<IllegalArgumentException>("Invalid URL syntax.") {
+            ClusterMetricsInput(
+                path = path,
+                pathParams = pathParams,
+                url = url,
+                clusters = listOf()
+            )
+        }
+    }
+
+    @Test
+    fun `test URI fields provided and url contains invalid characters`() {
+        // GIVEN
+        path = "/_cluster/health"
+        pathParams = "index1,index2,index3,index4,index5"
+        url = "http://localhost:9200/${ILLEGAL_PATH_PARAMETER_CHARACTERS.joinToString("")}"
+
+        // WHEN + THEN
+        assertFailsWith<IllegalArgumentException>("Invalid URL syntax.") {
+            ClusterMetricsInput(
+                path = path,
+                pathParams = pathParams,
+                url = url,
+                clusters = listOf()
+            )
+        }
+    }
 }