diff --git a/apps/hash-frontend/package.json b/apps/hash-frontend/package.json
index 29737db2b3d..b9dcb0a1e32 100644
--- a/apps/hash-frontend/package.json
+++ b/apps/hash-frontend/package.json
@@ -105,7 +105,7 @@
     "marked": "4.3.0",
     "material-ui-popup-state": "4.1.0",
     "millify": "6.1.0",
-    "next": "15.5.18",
+    "next": "15.5.21",
     "next-seo": "6.8.0",
     "nextjs-progressbar": "0.0.16",
     "notistack": "2.0.8",
diff --git a/libs/@local/hash-isomorphic-utils/package.json b/libs/@local/hash-isomorphic-utils/package.json
index 1fe0da0d493..9226fd07440 100644
--- a/libs/@local/hash-isomorphic-utils/package.json
+++ b/libs/@local/hash-isomorphic-utils/package.json
@@ -71,7 +71,7 @@
     "@vitest/coverage-istanbul": "4.1.10",
     "eslint": "9.39.4",
     "graphql": "16.11.0",
-    "next": "15.5.18",
+    "next": "15.5.21",
     "react": "19.2.6",
     "rimraf": "6.1.3",
     "typescript": "5.9.3",