GHSA-48hr-524c-v5w3: Nuxt: Unauthorized Component Instantiation via Server Island Props

Impact Nuxt server islands accept props via the /__nuxt_island/ endpoint. When an application has a server island component that forwards props directly into Vue's dynamic component resolution (<component :is>, resolveDynamicComponent, or h()), an attacker can pass a plain string value (rather than a component definition) to instantiate any globally-registered Vue component or any native HTML element. For example: { "as": "SomeGlobalComponent" } ...resolves and renders SomeGlobalComponent if it is globally registered, even though the attacker should only be able to drive props for the island's declared component. Similarly, { "as": "iframe" } renders an <iframe> element. Unlike the primary RCE vector (GHSA-9473-5f9j-94wq), this does not require vue.runtimeCompiler to be enabled. A plain string prop is sufficient to trigger component resolution. The template/render key guard that addresses the RCE vector does not block plain string values. Some component libraries expose a polymorphic as / asChild prop that forwards its value into <component :is>; @nuxt/ui (via reka-ui) is a widely used example. An application is affected if such a component receives the attacker-controlled value inside a server island. Note this does not require explicit prop forwarding: island props the island component does not declare fall through as attributes onto its single root element, so an island whose root is a reka-ui / @nuxt/ui component receives the attacker's as value implicitly. Unlike the RCE vector, no vue.runtimeCompiler is required, which makes this vector reachable in more configurations. These libraries are not themselves vulnerable; they are noted only because they commonly provide the dynamic-component sink. Installing @nuxt/ui does not by itself register any component as a server island: the application must define the island (a .server.vue file). Mitigating factors - Exploitation requires a server island component that puts an attacker-controlled value onto a dynami