Nuxt is an open-source web development framework for Vue.js. From 3.13.0 until 4.6.2, the server-island renderer serializes raw useHeadSafe entry input into the island response without preserving the safe-input marker, and NuxtIsland later inserts that input into the page head as an ordinary entry. An application that passes attacker-controlled data to useHeadSafe in a .server.vue component or page, or in a component rendered through NuxtIsland, can therefore render values normally removed by the allowlist, including event-handler attributes or executable script content, resulting in stored cross-site scripting in the application origin. This issue is fixed in version 4.6.2 .