diff --git a/server/routers/api-router.js b/server/routers/api-router.js
index 05c95375..683b2103 100644
--- a/server/routers/api-router.js
+++ b/server/routers/api-router.js
@@ -164,6 +164,9 @@ router.get("/api/badge/:id/status", cache("5 minutes"), async (request, response
 
     try {
         const requestedMonitorId = parseInt(request.params.id, 10);
+        if (Number.isNaN(requestedMonitorId)) {
+            throw new Error("Invalid monitor ID");
+        }
         const overrideValue = value !== undefined ? parseInt(value) : undefined;
 
         let publicMonitor = await R.getRow(
@@ -242,6 +245,9 @@ router.get("/api/badge/:id/uptime/:duration?", cache("5 minutes"), async (reques
 
     try {
         const requestedMonitorId = parseInt(request.params.id, 10);
+        if (Number.isNaN(requestedMonitorId)) {
+            throw new Error("Invalid monitor ID");
+        }
         // if no duration is given, set value to 24 (h)
         let requestedDuration = request.params.duration !== undefined ? request.params.duration : "24h";
         const overrideValue = value && parseFloat(value);
@@ -312,6 +318,9 @@ router.get("/api/badge/:id/ping/:duration?", cache("5 minutes"), async (request,
 
     try {
         const requestedMonitorId = parseInt(request.params.id, 10);
+        if (Number.isNaN(requestedMonitorId)) {
+            throw new Error("Invalid monitor ID");
+        }
 
         // Default duration is 24 (h) if not defined in queryParam, limited to 720h (30d)
         let requestedDuration = request.params.duration !== undefined ? request.params.duration : "24h";
@@ -374,6 +383,9 @@ router.get("/api/badge/:id/avg-response/:duration?", cache("5 minutes"), async (
 
     try {
         const requestedMonitorId = parseInt(request.params.id, 10);
+        if (Number.isNaN(requestedMonitorId)) {
+            throw new Error("Invalid monitor ID");
+        }
 
         // Default duration is 24 (h) if not defined in queryParam, limited to 720h (30d)
         const requestedDuration = Math.min(request.params.duration ? parseInt(request.params.duration, 10) : 24, 720);
@@ -450,6 +462,9 @@ router.get("/api/badge/:id/cert-exp", cache("5 minutes"), async (request, respon
 
     try {
         const requestedMonitorId = parseInt(request.params.id, 10);
+        if (Number.isNaN(requestedMonitorId)) {
+            throw new Error("Invalid monitor ID");
+        }
 
         const overrideValue = value && parseFloat(value);
 
@@ -534,6 +549,9 @@ router.get("/api/badge/:id/response", cache("5 minutes"), async (request, respon
 
     try {
         const requestedMonitorId = parseInt(request.params.id, 10);
+        if (Number.isNaN(requestedMonitorId)) {
+            throw new Error("Invalid monitor ID");
+        }
 
         const overrideValue = value && parseFloat(value);