diff --git a/test/harness/package-lock.json b/test/harness/package-lock.json
index 0bb201f5f..4711c00d0 100644
--- a/test/harness/package-lock.json
+++ b/test/harness/package-lock.json
@@ -11,7 +11,7 @@
       "devDependencies": {
         "@github/copilot": "^0.0.411",
         "@modelcontextprotocol/sdk": "^1.26.0",
-        "@types/node": "^25.2.0",
+        "@types/node": "^25.3.0",
         "openai": "^6.17.0",
         "tsx": "^4.21.0",
         "typescript": "^5.9.3",
@@ -1025,13 +1025,13 @@
       "license": "MIT"
     },
     "node_modules/@types/node": {
-      "version": "25.2.0",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-25.2.0.tgz",
-      "integrity": "sha512-DZ8VwRFUNzuqJ5khrvwMXHmvPe+zGayJhr2CDNiKB1WBE1ST8Djl00D0IC4vvNmHMdj6DlbYRIaFE7WHjlDl5w==",
+      "version": "25.3.0",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-25.3.0.tgz",
+      "integrity": "sha512-4K3bqJpXpqfg2XKGK9bpDTc6xO/xoUP/RBWS7AtRMug6zZFaRekiLzjVtAoZMquxoAbzBvy5nxQ7veS5eYzf8A==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
-        "undici-types": "~7.16.0"
+        "undici-types": "~7.18.0"
       }
     },
     "node_modules/@vitest/expect": {
@@ -2660,9 +2660,9 @@
       }
     },
     "node_modules/undici-types": {
-      "version": "7.16.0",
-      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.16.0.tgz",
-      "integrity": "sha512-Zz+aZWSj8LE6zoxD+xrjh4VfkIG8Ya6LvYkZqtUQGJPZjYl53ypCaUwWqo7eI0x66KBGeRo+mlBEkMSeSZ38Nw==",
+      "version": "7.18.2",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.18.2.tgz",
+      "integrity": "sha512-AsuCzffGHJybSaRrmr5eHr81mwJU3kjw6M+uprWvCXiNeN9SOGwQ3Jn8jb8m3Z6izVgknn1R0FTCEAP2QrLY/w==",
       "dev": true,
       "license": "MIT"
     },
diff --git a/test/harness/package.json b/test/harness/package.json
index 65edf4cbc..1c9eb2997 100644
--- a/test/harness/package.json
+++ b/test/harness/package.json
@@ -13,7 +13,7 @@
   "devDependencies": {
     "@github/copilot": "^0.0.411",
     "@modelcontextprotocol/sdk": "^1.26.0",
-    "@types/node": "^25.2.0",
+    "@types/node": "^25.3.0",
     "openai": "^6.17.0",
     "tsx": "^4.21.0",
     "typescript": "^5.9.3",