PT-2026-68936 · Npm · Nuxt

Published

2026-08-05

·

Updated

2026-08-05

CVSS v3.1

4.8

Medium

VectorAV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N

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:
json
{ "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 dynamic-component path (<component :is>, resolveDynamicComponent, h(), or a polymorphic as / asChild prop), either explicitly or via attribute fallthrough when the island's root is such a component.
  • Reachable components are limited to what is actually in the island app's global registry. In a default pages-enabled app that is RouterView and RouterLink (both registered globally by the pages router plugin, which runs even in component islands), plus any components/global/ component and any component a module registers globally. RouterLink in particular renders an attacker-influenced <a> (and, because an island that declares no props forwards all props, to and other RouterLink props ride the same fallthrough). Vue built-ins (Transition, KeepAlive, Teleport, Suspense) and Nuxt auto-imports (ClientOnly, NuxtLink, NuxtPage, etc.) are NOT in the island app's global registry and cannot be resolved this way; an unresolved name instead renders as a native HTML element (the element-injection half of this issue).
  • Declaring the props an island accepts, or setting inheritAttrs: false on it, prevents an undeclared as from falling through to a polymorphic root and neutralizes this vector.
  • Arbitrary JavaScript execution is not possible through this vector (no template/render compilation).
  • Island component names are constrained to the build-time component registry; an attacker cannot resolve arbitrary components.

Affected versions

Nuxt >=3.1.0 <3.21.10 and >=4.0.0 <4.5.1, with component islands active. The island prop-forwarding behavior has existed since server islands were introduced in v3.1.0, and this vector does not depend on vue.runtimeCompiler. Nuxt 2 is not affected.
Note the patch (below) closes the implicit attribute-fallthrough path, which is the majority case. An island that explicitly forwards an untrusted prop into dynamic component resolution (or forwards it under a prop name other than as) remains the application's responsibility in every version; see Workarounds.

Patches

Fixed in nuxt@4.5.1 and nuxt@3.21.10. Patched releases reject a top-level as island prop (HTTP 400 at the / nuxt island/ endpoint). This closes the implicit path: island props an island does not declare fall through as attributes onto its single root, so a top-level as would otherwise reach a polymorphic root component's as prop (the reka-ui / @nuxt/ui convention) and drive dynamic component resolution without the author binding it. Rejecting the top-level as prop blocks that fallthrough while leaving nested data and other prop names untouched.
The framework deliberately does not attempt to block every case: it cannot safely tell a string used as data from one used as a component selector, and it has no island-local hook into Vue's h() or resolveDynamicComponent(). An island that explicitly forwards an untrusted value into <component :is> / h() / resolveDynamicComponent(), or that forwards it under a different polymorphic prop name, is therefore not covered by the patch and must follow the guidance below. The Nuxt documentation now warns against this.

Workarounds

Upgrade to nuxt@4.5.1 or nuxt@3.21.10. That upgrade also removes the related object-prop RCE (GHSA-9473-5f9j-94wq). In addition, in any version:
  1. Do not forward island props into <component :is>, resolveDynamicComponent, or h(). Map an untrusted discriminator through a closed allowlist of imported component definitions instead of passing the raw prop value.
  2. Declare the props an island accepts, or set inheritAttrs: false on it, so request input cannot fall through to a polymorphic root component.
  3. Avoid registering sensitive components globally that could leak information if instantiated by an attacker.

Fix

RCE

Found an issue in the description? Have something to add? Feel free to write us 👾
dbugs@ptsecurity.com

Weakness Enumeration

CWE-20

Related Identifiers

GHSA-48HR-524C-V5W3

Affected Products

Nuxt