diff --git a/package-lock.json b/package-lock.json
index 5582598..56fb93a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -30,7 +30,7 @@
         "cors": "^2.8.6",
         "express": "^5.0.1",
         "winston": "^3.18.3",
-        "zod": "^3.24.1"
+        "zod": "^4.3.6"
       },
       "bin": {
         "github-advisory-mcp": "dist/index.js"
@@ -5701,9 +5701,9 @@
       }
     },
     "node_modules/zod": {
-      "version": "3.25.76",
-      "resolved": "https://registry.npmjs.org/zod/-/zod-3.25.76.tgz",
-      "integrity": "sha512-gzUt/qt81nXsFGKIFcC3YnfEAx5NkunCfnDlvuBSSFS02bcXu4Lmea0AFIUwbLWxWPx3d9p8S5QoaujKcNQxcQ==",
+      "version": "4.3.6",
+      "resolved": "https://registry.npmjs.org/zod/-/zod-4.3.6.tgz",
+      "integrity": "sha512-rftlrkhHZOcjDwkGlnUtZZkvaPHCsDATp4pGpuOOMDaTdDDXF91wuVDJoWoPsKX/3YPQ5fHuF3STjcYyKr+Qhg==",
       "license": "MIT",
       "funding": {
         "url": "https://github.com/sponsors/colinhacks"
diff --git a/package.json b/package.json
index adc208a..4752600 100644
--- a/package.json
+++ b/package.json
@@ -52,7 +52,7 @@
     "cors": "^2.8.6",
     "express": "^5.0.1",
     "winston": "^3.18.3",
-    "zod": "^3.24.1"
+    "zod": "^4.3.6"
   },
   "devDependencies": {
     "@ai-sdk/azure": "^3.0.27",