diff --git a/package-lock.json b/package-lock.json
index f02f031c6..eeccc8200 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -17547,7 +17547,7 @@
         "undici": "^7.10.0",
         "ws": "^8.16.0",
         "yargs": "^17.7.2",
-        "zod": "^3.23.8"
+        "zod": "^4.3.6"
       },
       "bin": {
         "gemini": "dist/index.js"
@@ -17675,6 +17675,15 @@
         "node": ">=18"
       }
     },
+    "packages/cli/node_modules/zod": {
+      "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"
+      }
+    },
     "packages/core": {
       "name": "@google/gemini-cli-core",
       "version": "0.38.1",
@@ -17744,7 +17753,7 @@
         "undici": "^7.10.0",
         "uuid": "^13.0.0",
         "web-tree-sitter": "^0.25.10",
-        "zod": "^3.25.76",
+        "zod": "^4.3.6",
         "zod-to-json-schema": "^3.25.1"
       },
       "devDependencies": {
@@ -17941,6 +17950,15 @@
         "uuid": "dist-node/bin/uuid"
       }
     },
+    "packages/core/node_modules/zod": {
+      "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"
+      }
+    },
     "packages/devtools": {
       "name": "@google/gemini-cli-devtools",
       "version": "0.38.1",
@@ -17962,7 +17980,7 @@
       "license": "Apache-2.0",
       "dependencies": {
         "@google/gemini-cli-core": "file:../core",
-        "zod": "^3.23.8",
+        "zod": "^4.3.6",
         "zod-to-json-schema": "^3.23.1"
       },
       "devDependencies": {
@@ -17973,6 +17991,15 @@
         "node": ">=20"
       }
     },
+    "packages/sdk/node_modules/zod": {
+      "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"
+      }
+    },
     "packages/test-utils": {
       "name": "@google/gemini-cli-test-utils",
       "version": "0.38.1",
@@ -17998,7 +18025,7 @@
         "@modelcontextprotocol/sdk": "^1.23.0",
         "cors": "^2.8.5",
         "express": "^5.1.0",
-        "zod": "^3.25.76"
+        "zod": "^4.3.6"
       },
       "devDependencies": {
         "@types/cors": "^2.8.19",
@@ -18024,6 +18051,15 @@
       "integrity": "sha512-30sjmas1hQ0gVbX68LAWlm/YYlEqUErunPJJKLpEl+xhK0mKn+jyzlCOpsdTwfkZfPy4U6CDkmygBLC3AB8W9Q==",
       "dev": true,
       "license": "MIT"
+    },
+    "packages/vscode-ide-companion/node_modules/zod": {
+      "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/packages/cli/package.json b/packages/cli/package.json
index b81561fa1..c20314da8 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -69,7 +69,7 @@
     "undici": "^7.10.0",
     "ws": "^8.16.0",
     "yargs": "^17.7.2",
-    "zod": "^3.23.8"
+    "zod": "^4.3.6"
   },
   "devDependencies": {
     "@google/gemini-cli-test-utils": "file:../test-utils",
diff --git a/packages/core/package.json b/packages/core/package.json
index 1621fd20d..b9bc8ddbb 100644
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -87,7 +87,7 @@
     "undici": "^7.10.0",
     "uuid": "^13.0.0",
     "web-tree-sitter": "^0.25.10",
-    "zod": "^3.25.76",
+    "zod": "^4.3.6",
     "zod-to-json-schema": "^3.25.1"
   },
   "optionalDependencies": {
diff --git a/packages/sdk/package.json b/packages/sdk/package.json
index 141807afc..f8c36cb21 100644
--- a/packages/sdk/package.json
+++ b/packages/sdk/package.json
@@ -23,7 +23,7 @@
   ],
   "dependencies": {
     "@google/gemini-cli-core": "file:../core",
-    "zod": "^3.23.8",
+    "zod": "^4.3.6",
     "zod-to-json-schema": "^3.23.1"
   },
   "devDependencies": {
diff --git a/packages/vscode-ide-companion/package.json b/packages/vscode-ide-companion/package.json
index 710acd03a..c56a0e703 100644
--- a/packages/vscode-ide-companion/package.json
+++ b/packages/vscode-ide-companion/package.json
@@ -140,6 +140,6 @@
     "@modelcontextprotocol/sdk": "^1.23.0",
     "cors": "^2.8.5",
     "express": "^5.1.0",
-    "zod": "^3.25.76"
+    "zod": "^4.3.6"
   }
 }