Nuxt: Incomplete fix for GHSA-934w-87qh-qr26: a `javascript:` URL prefixed with an ASCII control character executes from `<NuxtLink>` when `pages` is disabled

Impact

An application that renders <NuxtLink :to="..."> with a value it does not control can be made to render an anchor whose href executes script in the application's origin when clicked.

This is an incomplete fix for GHSA-934w-87qh-qr26 (CVE-2026-53722). It only affects applications running without a pages/ directory, where pages resolves to false and Nuxt registers its own router in place of vue-router. Applications using vue-router are not affected.

Prefixing javascript: with an ASCII C0 control character, for example %01, meant the value was not recognised as having a protocol. It was classified as an internal route and so never reached the protocol check added in GHSA-934w-87qh-qr26, and the router used for pages: false passed it through to the rendered href unchanged. Browsers strip the leading control character and run the result as a script URL.

Both <NuxtLink custom> and the default anchor are affected, and the href is present in the server-rendered HTML.

Mitigating factors

• The application must have pages disabled (no pages/ directory, or pages: false).
• The application must bind untrusted input to :to.
• A victim must click the rendered link.

Affected versions

nuxt <4.6.0, including all Nuxt 3 releases. Versions before 4.4.7 and 3.21.7 are also affected by GHSA-934w-87qh-qr26.

Patches

Fixed in [email protected]. Nuxt 3 reached end of life on 31 July 2026 and will not receive a fix.

Anchor href values are now checked for script-capable protocols wherever they are rendered, including the router used when pages is disabled. Protocol detection also moved to the platform URL parser, so a URL is classified the same way the browser will read it.

Workarounds

Upgrade to [email protected] or later. If you cannot upgrade, including on Nuxt 3, validate values before binding them to :to, for example by rejecting anything that is not a path beginning with a single /.